In association withTHE NATURAL HISTORY MUSEUM

DINOSAUREyewitness

Thescelosaurusskull

Iguanodon fibula(calf bone)

Ammonite

Ornithischianvertebra

Horsetail

Zanclodonsuevicussnout

Redwood branch

Ornithischiantail vertebra

DINOSAUREyewitness

In association with THE NATURAL HISTORY MUSEUM

Written by

DR DAVID NORMANAND

DR ANGELA MILNER

A Dorling Kindersley Book

Dogwoodleaves

Stegosaurtooth

Passionflowerleaves

GizzardStones

Cross-section ofIguanodon tail vertebra

Hadrosaur teeth

Chirostenotesclaw

Megalosaurustooth

Albertosaurusclaw

Project editor Susan McKeeverArt editor Lester CheesemanSenior editor Sophie Mitchell

Senior art editor Miranda KennedyManaging editor Sue Unstead

Managing art editor Roger PriddySpecial photography Colin Keates

PAPERBACK EDITION

Managing editors Linda Esposito, Andrew MacintyreManaging art editor Jane ThomasCategory publisher Linda Martin

Art director Simon WebbEditor Clare Hibbert

Reference compiler Sue NicholsonArt editors Andrew Nash, Joanna Pocock

Consultants Michael Benton, Dougal DixonProduction Jenny Jacoby

Picture research Celia DearingDTP designer Siu Yin Ho

This Eyewitness ® Guide has been conceived by Dorling Kindersley Limited and Editions Gallimard

Hardback edition first published in Great Britain in 1989.This edition first published in Great Britain in 2003

by Dorling Kindersley Limited,80 Strand, London WC2R 0RL

Copyright © 1989, © 2003, Dorling Kindersley Limited, LondonPenguin Group

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted

in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the copyright owner.

A CIP catalogue record for this book is available from the British Library.

ISBN 0 7513 6485 1

Colour reproduction by Colourscan, Singapore

Printed in China by Toppan Co., (Shenzhen) Ltd.

See our complete catalogue at

LONDON, NEW YORK, TORONTO, MELBOURNE, MUNICH, and DELHI

Hypsilophoonvertebrae

Coelurosaur neckvertebra

Ornithomimustoe

Monkey puzzlebranch

Tyrannosaurus rex tooth

Morosauruschevron bone

Dryosaurus femur(thigh bone)

Ginkgoleaves

Hadrosaurtoe bone

Contents

6What were the dinosaurs?

8Early discoveries

10Dinosaur landscape

12Little and large

14The long-necked beast

20The tale of defence

22Dinosaur diets

24Meat eaters

26Plant eaters

28Peculiar heads

30Three-horned face

32A tough skin

34Plated dinosaurs

36Fast movers

38Two feet or four?

40Ancient footprints

42Claws and their uses

Heterodontosaurus skull

44Eggs and nests

46Birth and growth

48Death of the dinosaurs

50Dinosaur or bird?

52How to find a dinosaur

54How to rebuild a dinosaur

56The timescale

60The end of an era

62Myths and legends

64Did you know?

66Classification of dinosaurs

68Find out more

70Glossary

72Index

6

What were the dinosaurs?BACK IN THE MISTS OF TIME, there lived an extraordinarygroup of animals. Called dinosaurs, they survived fornearly 150 million years, and then disappeared off the faceof the Earth in the most mysterious extinction ever. Manyof them were gigantic, but some were tiny, the size of achicken. Some were peaceful and ate only plants; otherswere fierce sharp-toothed flesh eaters. Dinosaurs werereptiles, just like the living iguana lizard on this page. Theyhad scaly skin and laid eggs. But unlike the lizard, whichhas short, sprawling legs, dinosaurs had long legs tucked undertheir bodies, which meant that they could move much moreefficiently. Many other reptiles shared the dinosaur world,swimming in the sea and flying in the air, but dinosaurs livedonly on land. We know about them today because their bones and teeth have been preserved in

rock as fossils.

6

DINOSAURS COULDN'T FLY!Flying reptiles, like the pterosaursshown here feeding on a Triceratopscarcass, shared the dinosaurworld, but were not dinosaurs.No dinosaur could fly.

HIPS CAN TELL A STORYDinosaurs fall into two main groups, according tothe structure of their hip bones. Saurischian, or"lizard-hipped" dinosaurs had hips in which the two lower bones pointed in opposite

directions. Ornithischian, or "bird-hipped" dinosaurs had the two

lower hip bones lying togetherbehind the back leg.

Tyrannosaurus rex(lizard-hipped)

Hip bones separate(saurischian)

Iguanodon(bird-hipped)

Hip bones next toeach other(ornithischian)

iguana lizard

Sharp claws

77

WHAT'S LEFT...One of the earliest dinosaurs to bediscovered was named after an iguana(pp. 8-9). Green and scaly, this iguanalooks prehistoric, and indeed has features in common with some dinosaurs,like the texture of the skin, and the sharp claws.

Nostril

Short sprawling legs

Characteristicscaly skin

Neck frill

Dinosaurs may have been this

colour

LIVING DINOSAUR?The tuatara is a rare, endangered species of lizardfound only on islands off the coast of New Zealand.Extinct relatives of the tuatara lived during thedinosaur age. The spines on its back are reminiscentof some dinosaurs' back spines.

HOW DINOSAURS EVOLVEDThe nearest living reptile relatives of dinosaurs arecrocodiles. Millions of years ago, an ancient crocodile-like ancestor, or thecodontian ("socket-toothed reptile") developed the habit of running onland. Over millions of years thecodontians changedthe way they moved their legs, became smaller, faster moving, and eventually evolved into theearliest dinosaurs.

"BIRD CROCODILE"Ornithosuchus

was a later,predatory

thecodontian that walked ontwo legs - a cousin of the firstdinosaurs.

IN THE WATERProterosuchus was an

early thecodontian that spent most of its time in the water.

UPRIGHT AND DANGEROUSStaurikosaurus was one of the earliest dinosaurs. Aflesh eater, its fully upright gaitmade it a fast mover, giving it anadvantage over the thecodontiansbefore it.

ON FOUR LEGSThecodontians like

Euparkeria left thewater to live on land,

walking on all-fours.

Early discoveriesALTHOUGH DINOSAUR remainshave been around for millions ofyears, people knew nothing aboutthese extraordinary creatures untilthe 19th century. One of the firstpeople to discover dinosaur boneswas an English doctor called GideonMantell, who collected rocks and fossilsas a hobby. In 1820 Dr Mantell, with his wife Mary Ann, found some large teeth embedded in stone. Mantell had never seenteeth quite like them before, and when hefound some bones nearby, he began to dosome serious research into the find. After a lotof work, Dr Mantell concluded that the teeth

and bones had belonged to some kind of giant reptile, which he namedIguanodon, meaning “Iguana tooth” (pp. 6-7). Two other giant reptileswere discovered in Britain soon afterwards, named Megalosaurus andHylaeosaurus. But it was not until 1841 that these creatures were givena group name. An eminent scientist of the time, Sir Richard Owen,declared that they should be called “Dinosaurs”, meaning“terrible lizards”. Thus began an exciting time of discovery in thescientific world. The great dinosaur hunt was on.

8

DINOSAUR MANThis cartoon shows Sir RichardOwen, the man who invented

the name Dinosaur. He is sittingastride a giant ground sloth

(a fossil mammal that was found inSouth America).

Tooth fromupper jaw

Worn edge

Horn on nose was actuallya thumb spike

Long whiplash tail like an iguana lizard

Gideon Mantell'soriginal drawing of

Iguanodon

Iguanodontooth fromlower jaw

THE FIRST TEETHStill embedded in the gritty stone inwhich they were found by theMantells, are the original Iguanodonteeth. The top edges of the dinosaur'steeth were worn down by chewingplants (pp. 26-27).

A ROUGH SKETCHDr Mantell had discovered a collection

of bones and teeth. But what on earthhad the owner of the bones looked

like when it was alive? Mantell pic-tured it as a gigantic lizard, a bit

like an iguana. He drew a pictureof it perched on a branch, with

its thumb spike (of which hehad found only one) placed on

its nose!

9

Backbones fusedtogether

MORE BONESMore bones from Iguanodon found by GideonMantell include this portion of the backbonewhich fitted between the hips of the animal.

Part of anIguanodonbackbone

MONSTERS IN THE PARKThese two concrete models of Iguanodon were made by the sculptor Benjamin

Waterhouse Hawkins in the last century. Although inaccurate - Iguanodon looked nothinglike this (p. 39) - they can be seen to this day in the park at Crystal Palace, London.

DINNER IN A DINOSAURAs the interest in dinosaurs grew, a greatdisplay of giant models was mounted in thegardens of London's Crystal Palace. Before theIguanodon model was finished, the sculptorheld a dinner party inside it for 20 people.

THE DISCOVERERAlthough he was a medical doctor by profession, GideonMantell was an enthusiastic collector of rocks and fossils.Soon his home looked like a museum as his collection grew.

MYSTERY BONEIn 1809, long before the word

"dinosaur" had been heardof, a man called William

Smith found some bonesin Sussex, England, in-

cluding this shin bone.At the time, he did

not realize what theywere. Only later

were they ident-ified as belonging

to Iguanodon.

Iguanodon tibia(shin bone)

1010

Dinosaur landscapeDINOSAURS LIVED on the Earth

for nearly 150 million years,and it is not surprising that their

world changed substantially during this time.Continents, at first just one great landmass,gradually drifted apart until they resembled themodern arrangement that we are familiar with.This meant that the climate changed as well, andboth these factors influenced the types of plantsthat grew. These changes happened slowly overmillions of years and animals adapted accordingly.At the beginning of the dinosaur age, low shrubbyfern-like plants dominated the landscape. Thencame a time when huge coniferous forests andgroves of cycadsflourished.Later on, thebiggest

change of all happened when thefirst flowering plants began toappear. Many plants and flowersthat the dinosaurs may have

eaten can still be seengrowing today.

FIR FEASTHerbivorous dinosaurs had ample

vegetation to satisfy their appetites.Duckbilled dinosaurs, such as

Parasaurolophus, above, could copewith tough plants because their jawsand teeth were so powerful. Even fir

needles posed no problem.

A DINOSAUR HOMEThis scene shows the type oflandscape that would have beenfamiliar to dinosaurs of about 130million years ago. Horsetails,ferns, and cycads abound.

Conifer:Pseudotsugamenziesii

ANCIENT PUZZLELiving monkeypuzzle trees arerelatives of oneswhich flourished longbefore dinosaurs evertrod the Earth.

Monkey puzzle:Araucaria araucana

CYCAD FRONDCycads were abundantduring most of thedinosaur reign, andare still to be seentoday, althoughthey are quiterare.

1111

Passion flower:Passiflora sp.

Cycad: Cycas revoluta

A MAGNOLIAIt is surprising tothink of dinosaurseating flowers, butwhen magnoliasappeared about100 million yearsago they were no doubtmunched upon by manyplant-eating dinosaurs.

Fern:Blechnum sp.

Fern: Marattia werneri

Dogwood:Cornus alba

Horsetail:Equisetumgiganteum

Magnolia: Magnolia loebneri

Ginkgo:Ginkgo biloba

Cherry Laurel: Prunus laurocerasus

"Otto Luykeres"

THE FLOWERINGThe first flowering plant appeared

during the last period of the dinosaurs'reign. Flowering plants can reproduce morequickly than other types, and they rapidly

came to dominate plant communitiesworldwide. Flowers changed the diets of

dinosaurs dramatically.

Holly: Ilex aquifolium

12

THE OWNER OF THE BONEThis Brachiosaurus is the type of dinosaur thatowned the massive leg bone (far right). The

huge, pillar-like forelimbs were longer thanthe hindlimbs - probably to help it to

reach up to the treetops for food.

A LOT OF PEOPLE think of dinosaurs asbeing massive creatures, big enough toreach the treetops, but there were also tinydinosaurs, ones that would not even reachyour knee. The biggest creatures ever towalk the Earth were the sauropod group ofdinosaurs, which were all plant eaters. For a long time, Brachiosaurus was the biggestsauropod that we knew much about.Weighing about 70 tons, it was 22 m (70 ft)long, and stood at 12 m (39 ft) high - about as tall as a four-storey building. But nowbones have been found belonging to evenlarger dinosaurs. Paralititan, found in Africa,was about the same weight as Brachiosaurusbut could have been up to 30 m (100 ft) long.Argentinosaurus, found in South America,

was around 40 m (130 ft) long and probably weighed as muchas 20 large elephants. By contrast with these quite peacefulgiants, the tiny dinosaurs like Compsognathus (far right) were mostly agile, crafty meat eaters, some no heavier than a cat.

AS TALL AS A HOUSEThis French engraving

shows a popular imageof dinosaurs as giants:

an alarming visi-tor to a Paris street

investigates a balconyon the fifth floor of a

tall building.

Little and large

FANTASTIC FEMURThe femur (upper leg bone) shown right

belonged to a Brachiosaurus. If you stood nextto a Brachiosaurus leg, you would hardly reach

past its knee bone! The gentleman (left) isexamining an Apatosaurus femur, which

measures 2.1 m (6 ft 9 in) long. Apatosaurus wasanother type of sauropod dinosaur.

Part of a large Brachiosaurusfemur, ending in knee joint

13

SMALL FRYCompsognathus (shown fossilized above) was one ofthe smallest dinosaurs known. Although this fossilis not much bigger than a cockerel, dinosaurskeletons have been found small enough to be neatly cradled in an adult’s hand! The specimenhere is probably not yet fullygrown - bigger examples of Compsognathushave been found.

Compsognathus was aboutthe size of a cockerel

IN ACTIONWhen alive,

Compsog-nathus was

a nimble,fast-running

predator.It had small,

sharply pointedteeth, and would

have fed on a varietyof small creatures. Its preywould have included insects,

frogs, snails, and small lizards,which all shared the dinosaur world.

Hand

Hind feet

Compsognathusskeleton

Tail

Neck

Skull

Stomach

14

THE MASSIVE CREATURE that can be seenspread across the next eight pages wasone of the biggest dinosaurs ever to walkthe Earth. It was called Diplodocus, andlike Brachiosaurus, below, it belonged to agroup of dinosaurs called sauropods (p. 12). Diplodocuslooked extraordinary with its long neck and tail, and a head that was tiny in proportion to the rest of its body. This type of body suited its lifestyle perfectly. It could reach up to feed at the tops of the very tall trees, like conifers, that grew at the time. Its small head allowed it to browse amongst the vegetation, where few other dinosaurs could reach. This type of

feeding needed a special type of neck - one that was strong, light,and flexible, in order to be raised and lowered easily. Havingstripped one area bare of food, it would have ambled off with itscompanions in search of new feeding grounds. If Diplodocus wasthreatened by a meat eater, its only defence would have been itsbulk, and its long, whip-like tail (pp. 20-21).

NECK SUPPORTThis head and neck belong toBrachiosaurus. Like Diplodocus, itmust have had powerful neckmuscles that could raise its head.It would also have needed astrong heart to pump blood athigh pressure so that it couldreach the brain.

The long-necked beast

Small skull comparedto size of body

SHORT ANDFLEXIBLE

Unlike Diplodocus,a predator such as

Tyrannosaurus rex (left) needed aneck that was short, powerful, and

flexible. It had to be short to sup-port the large vicious head. Flexibility

in the neck meant that Tyrannosaurus rexcould twist its head around to wrench flesh

from its prey.

A HARD NECKTriceratops' neck (left) needed to

be short and extremely strong inorder to support the weight of its

head. As well as using the forceof its head to wrench off tough vegetation, it

also fought and charged enemies with its threeformidable horns (pp. 30-31).

15

CRANING THE NECKThe design of a Diplodocus neck is

rather like that of a man-madecrane. The jib, which juts out from

the main tower and from which thehooks used for lifting things aresuspended, is like the dinosaur’sneck. The heavy base of the cranewhich keeps it from toppling overis like Diplodocus’ sturdy body. The

jib of a crane has to be light andstrong, so the engineer builds itwith a light metal framework.

Diplodocus had lightweight, butvery strong bones in its neck, whichit could raise and lower just like the

jib of a crane.

JURASSIC BROWSERSDue to its enormous size, Brachiosaurus must have spent most of its timeeating. Travelling as part of a herd, the dinosaur would have fed inriverside forests and open woodland containing conifers, cycads, and ferns.Its fossil remains have been found in Africa, Europe, and America. Byswinging its long neck, Brachiosaurus could reach the leaves of tall trees.Lowering it, the dinosaur could nibble at low-growing ferns.

Ribs for muscle attachment

Powerful joints between neck bones Hollowed-out areas to makethe neck bones light

Spines for muscle attachment

The beast continues...

16

The backbone storyThe body of Diplodocus was designed to bear and moveenormous weight, and the backbone, between shouldersand hips, was the powerhouse of the whole animal. The back-bones had to be strong enough to support the enormousweight of the neck, tail, and belly. They were alsohollowed out, however, for lightness. Narrow spines,pointing upwards from the top of the backbone, acted asanchor points for powerful back muscles. Long ribs pointingdownward curved around the belly, helping to hold thebackbone in position against the great weight of the belly,and protecting the internal organs of the animal.

Neck bone

Temple of Jupiter,Athens

LEGS LIKE PILLARSThe strong legs of Diplodocus supportedits body just as the pillars of this Greektemple support the heavy stone roof.

The limb bones were heavy and dense,capable of supporting the enormous

weight of the dinosaur.

Humerus (upper arm bone)

Radius(forearm bone)

Hand

Wrist

Ulna (forearm bone)

Scapula(shoulder blade)

17

BACKBONES AND BRIDGESThe design of Diplodocus’ back is rather like that of a modern-daysuspension bridge. The forelimbs and hindlimbs are like the piers on eitherside of the bridge. The cables, which pass over the piers, support the road ofthe bridge. These are like the dinosaur’s backbone, which passes over bothsets of limbs and uses the weight of the body to lift the neck and tail.

Ribs

The Menai suspensionbridge in Wales

Tibia (shin bone) Fibula

(calf bone)

The tail begins...

Femur(thigh bone)

Ischium(hip bone)

Pubis (hip bone)

Hipsocket

18

BALANCING ACTUntil recently, scientists believedthat sauropods could only walk onall-fours. But experts who havestudied the size and strength of thelegs, and the tail structure, agreethat sauropods often reared up ontheir hind legs to feed.

Diplodocus rearing up on itshind legs to feed

THE BOXING KANGAROOKangaroos sometimes rest or groom

themselves while sitting on theirhind legs, using the tail as a

balancing aid. They alsobalance on their tails while

fighting. Leaning only onthe tail, they can kick outwith their feet, as in this

picture. They do notusually wear boxing

gloves, however!

18

All about tailsTails can have a surprising number of uses. The most important one for living reptiles, as wellas dinosaurs, is that it provides an anchor point for theattachment of large leg-moving muscles, running from thesides of the tail bones to the top of the hind leg. Sauropoddinosaurs like Diplodocus often used their tails for balancing. Byrearing up and balancing on hind legs and tail, they would have extended

their reach into the treetops,perhaps gaining access

to better-quality food. Fast moving two-legged dinosaursused their tails to balance

while running.

Kangaroo and boxer engaged in combat

Ischium(hip bone)

Elongated chevron

Chevron bones becomemore flattened towardsthe middle of the tail

19

A STIFF TAILSome nimble meat-eating dinosaurs like

Deinonychus, above, ran with their tails stretchedout stiffly behind them. The tail acted as a

counterbalance, and may have helped insteering around corners. Most scientists now

agree that, unlike the model shown here,Deinonychus was probably feathered.

CERATOPIAN VERTEBRAThis tail vertebra belonged to

a ceratopian, or horneddinosaur (pp. 30-31). The two

side projections on the bonewere anchor points for strong

muscles running downthe side of the tail.

FORKED VERTEBRAThis bone belonged to a sauropoddinosaur called Morosaurus, nowrenamed Camarasaurus. Called a"chevron" bone, it hung down beneaththe tail bones, quite close to the hips(far left). At the bottom is a longnarrow spine, to which muscles wereattached - muscle attachment was theirmain function. All dinosaurshad chevron bones, as domodern-day reptiles.

Forked part of boneenclosed a large bloodvessel which ran justbeneath the backbone

A chevron bone wasattached here below

the tail vertebra

Anchor point fortail muscles

Ceratopiantail bone

Diplodocuschevron bone

DIPLODOCUS CHEVRONTowards the middle of Diplodocus' tail, the chevron bones

became more flattened and boat shaped, like this one,photographed from above. These types of chevron bones

may have acted as skids to protect the underside of the tailas it dragged along the ground.

19

Morosauruschevron

bone

Deinonychus

Flattened chevron

The tail goes on…

Attachment areafor tail muscles

20

The tale of defenceTAILS WERE A VERY USEFUL MEANS of defence for manyplant-eating dinosaurs, and what they lacked in teeth andclaws was compensated for by their ingenious tails. Somedinosaurs, like the sauropods, had long, thin tails whichthey used as whiplashes. Apart from their daunting size,this was their main form of defence. Armoured dinosaurs,or ankylosaurs, had bony clubs on their tails, as well asbeing protected from head to toe with body armour.Stegosaurs, or plated dinosaurs (pp. 34-35), sportedformidable sharp tail spikes which they used to lash outat attackers. Some modern-day reptiles use their tails inself-defence: crocodiles will lash out at an enemy withtheir heavy, scale-covered tails, and many lizards havelong whiplash-type tails. No living reptiles, however, havedefensive tails with attachments as spectacular as theformidable spikes and clubs used by some dinosaurs todefend themselves.

20

WALKING THORN BUSHThis armoured dinosaur, Gastonia, was the length of a large car. Unlike fellow ankylosaurEuoplocephalus (below right), Gastonia did not have a heavy tail club. However, big spines couldhave made its tail a formidable weapon. The rest of Gastonia’s body was also studded with sharp,defensive spines.

USEFUL TAILScelidosaurus was a plant eater thatrelied mostly on its armoured skinto protect it from predators. But itslong tail may have given it an extraadvantage. It could have used it tobalance while it reared up on hindlegs in order to run away from apursuing meat eater.

THORNY DEVILSome living reptiles, like this Moloch lizard, are sowell armoured from head to toe that they don't need a specialdefensive tail. Few predators would attempt an attack on thisspiky lizard. It lives in dry or desert areas of Australia.

Longmuscular

tail

Scelidosaurus

Bony studs

Tail bones Joint betweentail bones

Tail bones becomenarrower towardsthe end

2121

THE END OF THE TAILFinally, we reach the end of

Diplodocus' tail. Because they did nothave to support any muscle, the

bones at the tip have become narrowcylinders. This also makes the tail

into an effective whiplash.

SPIKE STORYShown here at half life-size, thisStegosaurus tail spike (pp. 34-35)would have been covered by atough layer of horn in life, andsharply pointed at the end. Swungagainst the soft underbelly of ameat eater, it would have inflicteda terrible, crippling wound.

Some lethal tailsAll the dinosaurs that used their tails indefence were four-footed and herbivorous (p. 26). Those dinosaurs that walked on twolegs, like the duckbills (p. 28) needed their tailsto balance, so they had no clubs or spikes. Theyhad to rely on speed or camouflage for defence.The whiplash used by some sauropods, likeDiplodocus, would have annoyed large meat

eaters, and probably caused quite a stingingpain. The fearsome-looking clubs and spikes

belonging to the ankylosaurs and stegosaurswere often used as a silent threat - rather

like saying "don't come any closer!"

A LASH OF THE WHIPHeavy and lumberingsauropods were in generalpoorly armed. But they couldinflict stinging blows onattackers with their whip-like tails.These tails were specially designed tolash out sharply - they ended in slenderbony rods (see below).

A SPIKY TAILThis is what the tail spikes of Stegosaurus wouldhave looked like when attached. The bony platesof the animal ran down the tail to meet the spikes,

which were confined to the tip.So when the tail was swished to

the side, the tip was the partthat moved fastest, causingthe most damage.

Joints begin todisappear

Rough area forattachment ofhorny covering

Stegosaurus tail spike

Sharp defensivespike

CLUBBED TAILThis armoured dinosaur's tail endedin a huge, heavy, bony club. This wasmade out of several chunks of bone, all

welded together into a single lump. Theclub sometimes measured as much as 1 m

(3 ft) across. The dinosaur, called Euoplocephalus,would have needed very powerful and flexible tailmuscles in order to swing such a tail around and todrive the club into an enemy.

Ankylosaurclubbed tail

Sauropodwhiplash

tail

Stegosaurusspiked tail

Tail bones reduced to narrowcylinders of bone

22

VEGETARIAN SKULLThis skull belonged to a huge plant eater, orherbivore, called Diplodocus. All of the thin,

pencil-like teeth are at the front of the mouth.Diplodocus would have used them like a

rake to draw in fern needles andleaves. Unable to chew,

Diplodocus simplyswallowed what

it raked in.

Dinosaur dietsMANY OF US IMAGINE DINOSAURS as being fearsome meat-eating creatures. But some were peaceful plant eaters thatsimply browsed amongst the treetops, tearing off leaves.Other dinosaurs were able to eat a mixed diet of meat andplants, like humans. Those that were not vegetariandid not confine themselves to dinosaur meat. Theywould have eaten anything that moved, includinginsects and birds. Fossilized dinosaur remainscan tell us a lot about what the animal atewhen it was alive. The most importantclues are to be found in the shape andarrangement of the jaws and teeth. Eventhe overall shape of a dinosaur's bodytells a story - meat eaters often had bigheads and short, powerful necks in orderto wrench lumps of meat off a kill. The longnecks of many plant eaters were useful forreaching up to the treetops to feed.

22

BY THE RIVERThis scene from 190 million years ago shows meat-eating dinosaurs,

swimming reptiles, and flyingpterosaurs sharing the same landscape.

But although these creatures did allexist at that time, it is unlikely that

prehistoric reptiles would havethronged together in this way.

Weaklowerjaw

Orbit (eye socket)

Pencil-like teeth

Diplodocus skull

23

Seismosaurus

23

SERIOUS TEETHThe fearsome rows of curved, serrated teeth in the Allosaurus skull (below)are typical of carnivores (meat eaters). The "windows" in the massive skullhelped to reduce its weight. Allosaurus may well have fed on the young ofherbivores such as Diplodocus (opposite). An adult Diplodocuswould have been too big to tackle, unless Allosaurushunted in packs.

DUAL DIET DINOSAURThe skull above belonged to Massospondylus. Its teeth, being neither serrated and stabbing, nor rake-like or grinding, were "multi-purpose". Small and coarse-edged, they could chew either meat or plants. Animals who can eat like this are called omnivores.

Orbit (eye socket)

Orbit (eye socket)

Allosaurus skull

Large cavity in front ofeye for jaw muscles

Large serrated teeth

Powerful lower jaw Massospondylus skull (below)

Smallcoarseteeth

SEISMOSAURUS SNACKThis monster sauropod had askull very similar to Diplodocus’(see left). Seismosaurus had peg-shaped teeth at the front of itsjaw. It used them to rake inconifer needles and leaves.

24

The kingTyrannosaurus rex is probably the bestknown (and most feared) of the carnosaurs.A formidable 12 m (39 ft) long, it had amassive skull with powerful jaws that heldserrated teeth up to 18 cm (7 in) long. Itprobably used its tiny arms to push itselfupright after it had been lying down.

Meat eatersALL THE MEAT-EATING DINOSAURS belongedto a group called Theropoda, which literallymeans "beast footed". Some of the meat-eatingdinosaurs were called carnosaurs or "fleshlizards" - large animals with big heads, power-ful legs, and short arms. Like all theropods, theywalked on two legs, probably not very fast be-cause of the bulk they had to carry. They hadbig heads to accommodate long jaws whichwere lined with huge curved teeth, serratedlike steak knives. Carnosaurs pursued and ateother dinosaurs, or else fed on corpses that theyfound. They would kill their prey with the help oftheir clawed feet and then tear off the flesh of thevictim with their hands - well-equipped with sharpclaws - and teeth. The other meat eaters were knownas coelurosaurs, or "hollow-tailed lizards". By con-

trast with the carnosaurs, they were lightly builtnimble creatures with long grasping arms and

hands, and long, narrow jaws. They couldrun very fast, in order to catch small

mammals and insects. After a carnosaurhad eaten its fill, a coelurosaur would

often move in to eat the scraps thatwere left.

Backward-curvingteeth gave

carnosaurs a bettergrip on a victim

Gorgosaurus lower jaw

SMALLBUT VICIOUSIt is hard to believethat a dinosaur tooth

(left) could be smallerthan a human incisor,

or cutting-tooth (right).This dinosaur tooth

belonged to Troodon,or "wounding

tooth".

25

LETHAL JAW BONEThis Gorgosaurus lower jaw (left)stretched the length of theanimal's skull. Powerful jawmuscles, reaching up behind theeye, were attached to the areawithout teeth. These would haveproduced a powerful bite, snapping

the jaw shut on impact with itsprey. The skull above, which

belonged to another carnosaur, showsthe same basic design.

Inner side of jaw bone

Bony tooth socket

Sharp serrated frontedge of tooth

Ceratosaurus skull (below)

THE BIGGEST...This large Megalosaurus tooth is ofa typical carnosaur shape, with its curved edgepointing backwards. The edges of the tooth aresharp, with saw-like serrations for cutting meat.The cracks on this specimen appeared duringfossilization.

A LOSING BATTLE?A Victorian etching shows Iguanodon (left) and Megalo-

saurus (right) fighting each other. Although Iguanodonhas been given sharp teeth by the artist, it was in

fact a plant eater, and would not have stoodmuch chance against the might of Megalo-

saurus. The spike on its nose was really onits thumb in life, and was its only realweapon of defence (pp. 8-9).

Cracks whichoccurred during

fossilization

NEW GNASHERMeat-eatingdinosaurs' teeth keptgrowing and wereconstantly replacedthroughout life. Thismegalosaur tooth isa "new" one.

LION'SSLICER

Meat-eating

animals, like lions,have developed special

slicing teeth. No dino-saur had a tooth like this.

SMALLER GNASHERNot all tyrannosaurteeth were huge. Thissmall one is curved,in order to hook intoits victim.

NUTHETES TOOTHStill embedded inrock, this toothcame from asmall meateater calledNuthetes.

Fine serrationslike thoseon a steakknife

The large, curved toothof Megalosaurus

26

Plant eatersMANY OF THE DINOSAURS were plant eaters, including thebiggest of all, the sauropods (pp. 12-13). Eating a diet of plantscauses animals many more problems than eating meat. Plantsare made of tough materials like cellulose and woody lignin,and need to be broken down before digestion can take place in

the animal's stomach. Plant-eating dinosaurs copedwith their diet in a variety of ways: the sauropods didnot chew at all, but simply swallowed raked-in veg-etation. This passed directly to the stomach, and was

ground up by deliberately swallowed "gizzard stones"(gastroliths), or fermented by bacteria, as in a cow's

stomach. The hadrosaurs, or duckbilled dinosaurs,had special teeth which ground and chopped theirfood before they swallowed it. Ceratopianstackled tough plants with their extra-strong

jaws and scissor-like teeth.All of the bird-hipped

dinosaurs (p. 6) wereplant eaters.

Plant-eatingdinosaurswould haveeaten coniferssuch as thisyew leaf

Ceratopianbeak SCISSOR TOOTH

This tooth came from a ceratopiandinosaur, like Triceratops (below).

After tearing off the vegetation withits beak (far left), it would then havesliced it up with its sharp teeth.

TINY TEETHThis jaw camefrom Echinodon,one of the smal-lest plant-eatingdinosaurs. Thetiny teeth hadspiky edges, likethose of aniguana lizard,which eats amixed diet ofplants and meat.

Main jaw bone

Notch forreplacement

tooth to slot in

Cycad plant Pine cone

CROPPING BEAKA beak like this ceratopian one (p. 30) was ideal forcropping tough plants. The rough grooves and pits markthe place where the horny covering of keratin wasattached. The lower, wider part of the bone (called thepredentary) fitted tightly against the lower jaw.

BUILT TO CHEWDinosaurs like this Triceratops (pp. 30-31)ate tough, fibrous plants (above). Triceratops,like many ceratopians, had extremely powerfuljaws and sharp teeth to help it to cope withits diet.

TOUGHAND STRINGY

Some experts believe that ceratopiandinosaurs evolved specially to eat new kindsof tough plants. They would have eaten theleaves of palm-like cycads (left), and maybeeven tackled pine cones (above).

27

Sauropod spoon-like tooth

Root Horsetails

DENTAL SELECTIONSauropods' teeth were either spoon-shaped, for nipping, or peg-like, forraking in leaves. The ankylosaurs,or armoured dinosaurs (p. 33),had small teeth which were onlygood for eating softplants. No dinosaur hadflat teeth like human molars,which we use to crush and grindour food.

Sauropodpeg-like tooth

Ankylosaurtooth Human molar

Fern leaf

WEAR AND TEARTwo lower teeth of

an Iguanodon showthe before (left) and after (right) stages of wear

and tear. This would have been caused by the roughplant materials cellulose and lignin. Added to this wasthe inevitable grit and dust that the animal would have

eaten along with the plant.

Sharp edge of toothfor nipping Edmontosaurus jaw

Area worn downby eating plants

New teeth growing upBattery of diamond-shaped teeth

THE GREATEST GRINDERDuckbilled dinosaurs had the most spectacular array of teethof any plant-eating dinosaur. Hundreds of sharp, diamond-shaped teeth lined both sides of upper and lower jaws. Thegrinding surface formed by a duckbill's battery of teethacted like a chopping board, or a self-sharpening veg-etable grater, which crushed the plants. New teethconstantly grew to replace the worn ones, as can be seenhere, pushing up the top layer of teeth in this Edmontosaurusjaw (below).

Area for muscleattachment

CYCAD FOR TEAThis cycad frond is what aplant-eating dinosaur might havemunched on millions of years ago.

Jaw joint

EdmontosaurusBELLOWING BEAST

An Edmontosaurus, which ownedthe jaw above, looked like this. It hadabout 1,000 strong teeth in its cheek region. It may have

blown up the loose skin on its flat face to make a loudbellowing call. Duckbilled dinosaurs could also

store extra food in their cheeks, like hamsters.

FOOD FOR THOUGHTSome of the plants thatthe dinosaurs used toeat still grow today.These include cycads,

horsetails, ferns,and pine trees

(pp. 10-11).

Pineneedles

28

SOME DINOSAURS HAD most oddlyshaped heads, sprouting weird andwonderful projections of bone includinglumps, bumps, crests, spikes, andhelmets. And just as bizarre shapesor brightly coloured patches onreptiles, birds, and even mammalstoday attract attention, so did theodd shapes of some dinosaurs’heads. They were eye-catching,and could have been used to attracta mate, scare off an enemy, or simplyindicate how a dinosaur wasfeeling - happy or angry!They were often used inattack or defence - abony head could actlike a naturalsafety-helmet,

or a formidable head-butting device.The most spectacular heads belongedto a group of dinosaurs calledthe hadrosaurs, or duckbills,so-called because of theirbroad, toothless beaks

Peculiar heads

HEAD-CASESThe first two heads in this selection are

duckbills: Parasaurolophus,with its distinctive long

horn, and Corythosauruswith its "dinner-plate"

shaped crest. The broad, thickhead on the right belongs toPachycephalosaurus, one ofthe "bone-headed"dinosaurs.

Parasaurolophus skull

Toothlessbeak

Teeth start here

CREST FALLENDifferent hadrosaurs had differenthead shapes, but their bodies wereall quite similar. Some had headsthat were completely unadorned

with odd-looking projections. Thisdrawing from 1897 shows one of

the most common “crestless” types,Edmontosaurus. It used its broad,

duck-like beak to scoop up leaves.

29

GIVING A HOOTThe long hollow crest on the skull of

Parasaurolophus has puzzled experts foryears. At first it was thought to be a "snorkel",

or a reserve air tank used when the animal wasfeeding under water. Or perhaps it was an extension

of the nostrils, enhancing the creature's sense of smell. Now we know that the hollow tube was probably a

"resonator", through which the dinosaur could bellow or hoot in a distinctive way. Females of this species had smaller, less spectacular crests.

THE HEADBANGERThe head of Pachycephalosaurus

(meaning "thick headed reptile") was 80 cm (2 ft 7 in) long, and its dome

was made of solid bone. It used thisdome to head-but enemies, just as

sheep and goats use their horns.

DUCKBILL DINNERBecause hadrosaurs had toothless beaks,

they were often pictured wading inswamps, and feeding on soft water

plants. But in reality they weremainly land feeders, and could

tackle tough vegetationfrom trees, grindingit up with their powerful jaws (p. 26).

Parasaurolophusfeeding

PARROT HEADThis oddly shaped skull belonged to a Psittacosaurus, or "parrot lizard". Although it did not have many teeth, its sharp,deep beak could slice through toughleaves and woody stems.

BIRD BEAKPsittacosaurus had a sharp beak like a

parrot, but there the similarity ended!

REARING TO GOPachycephalosaurus may

well have reared up andbellowed loudly, as in the

picture, before charging an enemy.

Dome ofsolid bone

Bony spike

Pachycephalosaurus skull

Sharp,pointed beak

Psittacosaurusskull

Long crest was hollow inside

30

Three-horned faceTRICERATOPS, WHICH MEANS "three-horned face", belonged to a group ofdinosaurs known as ceratopians, or

horned dinosaurs. Eachceratopian had a large bony

frill pointing backwards from theskull and masking the neck, hornson the nose or over the eyes, and anarrow, hooked beak. Most were four-legged and stocky, like the rhinoceroses oftoday, and all were plant eaters. Many fossilsof ceratopians found in the same area suggestthat they roamed in herds, confronting a threateningmeat eater as a pack. As the ceratopians evolved, theirheadgear gradually became more pronounced. Triceratops,

the "king" of the ceratopians, lived at the end of the reign of the dinosaurs, and had themost spectacular array of horns and frills of all the ceratopians: its head tookup nearly one-third of its length. Withhead lowered and the horns pointingforward, all backed up by its enormousbulk, Triceratops must have provided aformidable defence to predators such asTyrannosaurus rex (p. 24).

Wavy edge of frill Nostril

Parrot-like beak

Triceratopsskull - front view

SKULL STORYBy far its most prominent feature, Triceratops'

heavy skull can tell us a lot about its way of life.Its jaw was built to tackle very tough and fibrous plantmatter. It used its narrow hooked beak to snip off plants,

which it then sliced up with its sharp, scissor-like teeth.Huge muscles which extended up into the frill powered the jaws.

The frill probably acted as an anchor for the jaw muscles, and alsoprotected the neck. Triceratops used its sharp horns mainly for defenceagainst tyrannosaurs, but it also used them in one-to-one combat. Themale Triceratops would lock horns with a member of its own kind and

head-wrestle, much as deer, antelope, and sheep do today.

Brown horn

LIKE A RHINOThis model reconstruction of Triceratops,

based on the study of complete skeletonsof the animal, is probably very close tolife. Here, the resemblance to modern

rhinoceroses is very striking.

Nose horn

31

SPIKY STYRACOSAURUSRoughly half the length of

Triceratops but no less impressive was Styracosaurus. It, too, had

an enlarged nose horn, and its frill had extra-long spikes, as well as several smaller ones. Styracosaurus would have looked very imposing if it lowered its head in display.

Jaw muscle wasattached here

Triceratopsskull - side view

Regalhorned lizard

PRESENT-DAY FRILLSome living lizards, like this

regal horned lizard, have hornsand frills too. Lizards use their

frills to intimidate enemies,expanding them to make

themselves look larger thanthey really are.

Frill supported endof jaw muscle here

A MAMMOTH TASKShown here in the process of reconstruction

is the three-horned skull of Triceratops.

Eye socket

32

A tough skinWHAT WAS dinosaur skin

like? Fossilized skinimpressions can tell us

that it was scaly, likereptile skin, and in some

cases armour-plated forextra protection. Dinosaur skin

was perfectly suited to life on land.Just like reptile skin, it was waterproof,

tough, and horny. Waterproof skin preventsan animal from drying out quickly in air, sun, or wind - animals like

frogs have to stay in moist conditions because their skin is thin and notwaterproof. Tough, scaly skin protects an animal while it moves abouton land, dragging the body over, or between, rough stones, or fallingover. Dinosaur skin impressions, like the ones shown here, are usuallysmall, because after death, animal skin rots away too quickly to befossilized. However, in a few rare cases, an almost entire bodyimpression has been preserved. The dinosaurs that leftthese impressions probably died in a dry area so thattheir skin became dried out, before being buried bywind-blown sand. The sand then turned into sand-stone over the years, and was so tightly packed

against the skin that when the skin disappeared, its exact shape andpattern remained in the stone. No one knows for sure what colourdinosaur skin was, or whether it had stripes or spots - dinosaursare most often shown in "muddy" shades of green and brown.

Polacanthusskin impression

A KNOBBLY COATThis knobbly skin impressioncame from an armoured dinosaur calledPolacanthus. Short-legged and squat, it was about 4 m (13 ft)long, and had sharp spines running along its back. These,combined with its overlapping bony plates, would havediscouraged hungry meat eaters from attacking.

Raisednodules forprotection

LIKE A CROCODILE?Crocodiles, being reptiles, have thesame type of skin as the dinosaurs - ideallyadapted to conditions on dry land. Theknobbly skin on this "smiling" crocodile islike the Polacanthus impression (left).

SOLITARY NODULEBony nodules like this onewere mixed in with theoverlapping plates onPolacanthus skin. Thesenodules "floated" in the skinbeneath the scales, as inliving reptiles.

ARMOUR-PLATED MAMMALWell protected by its bony armour,

the armadillo that lives today is likethe ankylosaurs, or armoured

dinosaurs (right). They, too, stayedlow to the ground while predators

were threatening. Few attackerswould have been able to get a grip

on their tough bodies.

COLOUR CO-ORDINATED

Dinosaurs may wellhave had brightly

coloured skin like thisagamid lizard. Skincolour can be useful ascamouflage, or as awarning signal. Thislizard probably useshis bright-green skinto mark out a territory,or to attract a mate.

33

THE COMPLETE BEASTThis is what Edmontonia, one of the largestankylosaurs, probably looked like when itwas alive. Its armour included spikes thatguarded its shoulders and flanks from attack,and rows of bony plates.

UNARMOURED AND SCALYQuite smooth compared to theankylosaurs, this skin impressioncame from a sauropod dinosaur,probably one like Diplodocus (pp.14-21). The skin was scaly, not bonylike the ankylosaurs, and would havegiven little protection against attack.The scales, although packed tightlytogether, had flexible edges wherethey touched, acting like "hinges"to allow easy movement.You can see from this impressionthat the scales varied in size,the smaller ones occurringwhere the skin had tobend a lot.

Bigger scaleswhere skin

did not haveto bend

Sauropodskin

impression

ANKYLOSAUR NODULEMany ankylosaur nodules looked likethis one. The flattened base wasattached to the creature's back, andthe broad central ridge providedprotection. In life, it was coveredby a horny scale (like a fingernail).In the picture, it is possibleto make out the pitted areaswhere this was attached.

Central ridgeof nodule

Smaller scalesfor flexibility

ALL ABOUT ANKYLOSAURSThe ankylosaurs had boneswhich were fused togetherto form a bony armour.The armoured "tanks"of the dinosaur world,

these creatures weresquat and very

heavy. They lookedrather like giantreptilian armadillos.They had small jawsand weak teeth, andate plants. They pro-

tected themselves fromlarge carnivores mainlyby crouching and clingingto the ground, relyingcompletely on their toughskins for defence.

34

THE PLATE DEBATEScientists have long argued about howStegosaurus’ plates were arranged. Here theyare alternated, but they are often shown inpaired rows. The plates were made of bonewith honeycomb-like spaces running through- not much use as defensive armour plating.

ONE OF THE MOST unusual groups of dinosaurs were thestegosaurs, named after the North American dinosaur,

Stegosaurus. Easily recognized by the double row ofplates running down their backs, stegosaurs also hadsharp spikes on the ends of their tails, used forlashing out in defence. Despite their fearsomeappearance, these dinosaurs were all plant eaters.They usually walked on all-fours, browsing onlow vegetation - a way of feeding which suited

their low-slung heads perfectly. Their small weakteeth could only handle soft plants. The word

“stegosaur” actually means “roof lizard”, because itwas once thought that the plates lay flat on

the dinosaur’s back, like tiles on a roof.Although this arrangement would haveprovided slightly better protection againstattack from carnosaurs, it is more likely thatthe plates stood upright in two rows along the stegosaur’s back. Somepeople think that the plateswere fixed to the skeleton,but they were actuallyembedded in thedinosaur’s thick skin.

A WEIRD STEGOSAURThis etching shows an early attempt to reconstruct aplated dinosaur - with hedgehog-like spines insteadof bony plates! However, there is evidence from hipbone fossils that one stegosaur at least, Stegosaurus,could have reared up onits hind legs like this.

Plated dinosaurs

Vertebral spine

Cone-shapedplate

Chevronbone

Broad, flatfeetSharp defensive spike

A STING IN THE TAILThe large, cone-shaped plates on

the back of Tuojiangosaurus give way totwo pairs of sharply pointed ones, which were

used as lethal weapons. Stegosaurs could swing theirmuscular tails from side to side with great force.

35

Long hind limbs

Short frontlimbs

Small narrow headwith walnut-sized

brain

The Chinese stegosaur,Tuojiangosaurus

PEA BRAINStegosaurs are

famous for having tinybrains in proportion to their

size. Stegosaurus had a brain the size of awalnut. This has given some people the idea

that dinosaurs were stupid or slow. Butstegosaurs' brains were obviously ample fortheir needs, as they managed to survive for

over 10 million years.

CLOSE-UP PLATEShown at half life-size, this is one of the

smaller plates from the neck region ofStegosaurus. These large, flat bones actedlike the sail of Dimetrodon (above left) to

warm or cool the animal. The plates wererichly supplied with blood, and Stegosauruswould have used this blood like water in a

central-heating system. Standing in thebreeze would have cooled the blood,while basking in the sun would have

raised its temperature, therebywarming the dinosaur.

POORLY DEFENDEDLike all stegosaurs, Tuojiangosaurus' flanks andbelly were vulnerable to attack. The spikes inthe tail were the main weapon used to fend offattacks of large meat-eating dinosaurs.

Some stegosaurs madeuse of solar power

WARMING UPDimetrodon was an early reptile

that lived before the dinosaurs.It used the large sail on itsback to absorb the heat ofthe sun on cool days,and so warm its body.Some plated dino-saurs did the same.

Stegosaurus plate

36

OSTRICH LOOKALIKEStruthiomimus, or “ostrich mimic”, lookedremarkably like an ostrich, and probablyran in a very similar way. Scientists eventhink it probably had feathers. The main

difference is Struthiomimus’ long bony tail,and its clawed hands in place of wings.

Fast moversNOT ALL DINOSAURS WERE HUGE and lumbering. Some werebuilt for speed, either to flee attackers, or to pursue prey.Unlike fast-running living animals like horses, which are allfour-footed, fast-moving dinosaurs ran on their hind legsalone. As a result, all the fast movers looked quite similar.They all tended to have long back legs, in order to take longstrides. Slender legs and narrow feet can be moved quicklyand so allowed the dinosaurs to run more efficiently. Therest of the body was usuallylight and fairly short, balancedby a slender tail. The armswere lightly built, with small-clawed hands, and the neckwas long, with a small head on thetop. Some of the nimble dinosaurscould reach speeds of 56 kph (35

mph) - almost as fast as a racehorse. They could take advantageof their speed in two ways: either to pursue a victim, or tobeat a hasty retreat from an attacker. Herbivorous andcarnivorous fast-moving dinosaurs were involved in akind of "race": plant eaters evolved faster and fastertypes in order to avoid being caught by ever-improving meat eaters.

TINY AND TOOTHYThis fast-moving dinosaur,Heterodontosaurus, was only about 1 m(3 ft) long. It had three different typesof teeth, but was still a herbivore.

Long neck wasstretched forward

as Gallimimus ran

Narrow feet for speed

A POOR GRIPClosely related to

Struthiomimus (above left)Gallimimus was remarkably

bird-like with its toothlessbeak. Its hands were notadapted for grasping things.

Gallimimus in motion

Stiffened tail forbalancing

SPRINTING DINOSAURSSmall, agile plant-eating dinosaurs likeHypsilophodon (below) were among thefastest runners. By measuring their legs andcomparing their shape to those of modernanimals, experts have estimated that theyreached speeds of 45 kph (30 mph).

37

LEGS FOR SPEEDA look at a pair of Hypsilophodonlegs shows us special features of fast-moving dinosaurs. The main

leg bones are slender, yet strong,and show signs of special bony

attachment areas for powerfulleg muscles. The joints are well

formed, and the feet narrow.It was once thought thatHypsilophodon lived in trees,because of its grasping toesand balancing tail (p. 62).

NIMBLE HUNTERAt less than 1 m (3 ft) long,

Compsognathus was one of thesmallest-known dinosaurs. A meateater, it used its agility and speed

to pursue lizards, frogs, and avariety of other small creatures.

SPEEDY BIRDApart from their long tails, arms, and bareskin, many of the small, speedy dinosaurs

were just like ostriches. Ostriches cannotfly, but they can run as fast as

Hypsilophodon did.

The legs of Hypsilophodon

Knee joint

Ostrich

Femur (thigh bone)

Slender feetand toes

Hypsilophodon inmotion

Strong ankle joints

38

A sauropodmother rearsto defend its

young

Hadrosaur toe

Triceratops toe

Scelidosaurus foot

“DON’T COME ANY NEARER!”This museum model shows amother Barosaurus rearing up on its two hind legs. It is defending its young against an attack by anAllosaurus. However, scientists arestill debating whether a hugesauropod would – or could – have behaved like this.

FOUR-LEGGED TOETriceratops always walked on fourlegs, so this Triceratops toe bonecould come from either the frontor back foot. The toe bone isbroader and more hoof-likethan the hadrosaur one(above). That is because the hadrosaur did not use its front feet so much. SOMETHING AFOOT?

This is the complete hind foot of an early plant-eating dinosaur calledScelidosaurus. It was heavily armoured with bony, jaw-breaking studs which ranthe length of its body. Scelidosaurus alwayswalked on four legs, and its hind foot wasstrong and broad, with four powerful toesto support the heavy body. The small firsttoe would have barely reached the ground.

HANDY SUPPORTThis hadrosaur toe bonefrom the “hand” is typicallyflattened and slightly hoof-like. It could support thedinosaur’s weight when itwas grazing on all-fours.

WHY DID SOME DINOSAURS WALKon four legs, while others walked on two? The answer is simple– dinosaurs walked in the waythat suited their lifestyle best.Most carnivores, for instance,walked on their hind legs,because they needed to use their hands to catch andhold on to their prey. Otherdinosaurs usually walked onall four legs, mainly becausetheir enormous size and weightneeded support from four sturdy“posts” underneath. However,fossil finds suggest that even a large,heavy herbivore such as Diplodocus(p. 14) was able to rear up on its hindlegs – for short periods, at least. Somedinosaurs, for example hadrosaurs, hadthe option of walking either on two orfour legs, depending on what they were

doing at the time. Mostly, it suited them to move around slowly on all-fours, so that they could browse onlow-growing vegetation. When they werealarmed, however, they could rear upand charge off on hind legs alone.These dinosaurs neededspecial “hands” thatallowed for weightsupport, as well as grasping.

Two feet or four? Hoof-likeclaw

Ankle bones

39

SPIKY CUSTOMERAlthough Iguanodon was

most often pictured ontwo legs wielding its thumb spike

(right), it actuallyspent much of its

time on all-fours.

SPIKY CUSTOMERAlthough Iguanodon was

most often pictured ontwo legs wielding its thumb spike

(right), it actuallyspent much of its

time on all-fours.

First toe

Flexible fifthfinger

Iguanodon hand

Fourth finger

Narrow, sharpclaw

Toes endingin hooves

Second finger

Thumb spike

Wrist bones

MULTI-PURPOSE HANDIguanodon's hand is remarkablebecause it shows clearly thedifferent uses to which a hand canbe put. The large thumb spike wasused as a fearsome defensiveweapon. The middle three fingers,which ended in hoof-like bones,were used exclusively for walkingon, and the fifth finger wasflexible, and used forholding food.

FEEBLE HANDSThe mighty Tyrannosaurus rex had

surprisingly small hands inproportion to its body, with only

two claws. They were too short tohold prey, but they may have beenused as anchors to grip the ground

when Tyrannosaurus rex rose fromresting.

HAND OR FOOT?We know this is a hand because of the sharp,narrow claws used for holding things, ortearing leaves off trees. It came from Plateosaurus,

a plant eater that fed on plants at ground level(on all-fours), and then reared up on its hind

legs to reach the treetops. The joints betweenthe bones allowed the hand to be bent back

to allow Plateosaurus to walk on all-fours.

40

AS WELL AS LEAVING their fossilized bones as evidence,dinosaurs also made their mark on the Earth in the

form of footprints. Tracks have been found wheredinosaurs walked in soft, swampy land, for examplealong riverbanks, in search of food and water. Later on, the prints would have dried and hardened in thesun. Eventually, through rain or flooding, water would

have brought more sand or mud which buried theprints until they gradually fossilized. Called trace

fossils, because they are not actually a part of ananimal, these footprints can tell us much about howdinosaurs moved. A lot of the same types of printsfound together, for instance, with smaller ones in the middle, suggests that some dinosaursmoved in herds, with the young onesprotected in the centre.

Ancient footprints

RUNNING ALLOVER THE WORLDDinosaur trackways have beenfound all over the world. Thesetracks found in Queensland,Australia, came from small meateaters, running together as a pack.Experts can judge the speed atwhich they were moving bymeasuring the distance betweenthe prints.

Toe bone

Iguanodon foot shownat reduced size

LEAVING EVIDENCE?This old etching shows an Iguanodon

leaving footprints while feeding ina forest. Footprints left in for-

ested areas would not have beenpreserved, however - they

would need to be madein more swampy land.

Upper foot bone

FOSSIL FOOTThe three-toed right foot of Iguanodon (above) had

to be very strong to support the great weight of the animal.Iguanodon probably walked on its toes, like cats and dogs do

today. The foot leaves a clover-leaf shaped footprint, many ofwhich have been found in southern Britain. The heavier the

dinosaur, the better the footprint (right).

A GOOD IMPRESSIONShown here at almost life-size is part of the fossil-ized impression of an Iguanodon's left hind foot. Al-though it may seem huge, this footprint is quite smallcompared to some that have been found. A large, adultIguanodon left footprints 90 cm (36 in) long. The creatureprobably weighed up to 2 tons. This print was probablymade by a youngster weighing only about half a ton.

Iguanodon footprint

41

42

CREEPY CLAWSThis feathered dinosaur is Velociraptor, or

“quick robber”. Its jaws were lined withrazor-sharp teeth, but its most formidable

weapons were four sets of deadly, hookedclaws. Using its hand to hold on to its prey,

Velociraptor would have been agile enough toraise a clawed foot and deliver a killer kick,

slashing through its victim’s flesh.NOT FOR

ATTACKThis claw belongs to Ornithomimus. Although this

dinosaur was a meat-eater, its claws were quite flattened,and would not have been much use for defence or attack.

Tubercle(swelling)for strongmuscleattachment

THUMB CLAWThis smallish claw came fromthe thumb of Massospondylus.

The slight swelling at the basewas where a strong muscle

was attached.

Claws and their usesCLAW BONES ALL HAVE stories to tell about the

lifestyle of their owners. Dinosaurs that huntedand killed other animals tended to have very narrow,

sharp, curved claws, like the talons on the foot ofan eagle. They used their clawslike daggers, to gain a securehold and to stop their

unfortunate victim fromescaping. The clawsalso helped to injure,or even kill, the prey.Perhaps the mostterrifying clawedpredator of the

dinosaur age was Deinonychus, or "terribleclaw". It had a huge sickle-like claw on itssecond toe, and long arms with three-fingeredclawed hands. It would leap on its victim,slashing with its claws, and using its long tail tobalance. Plant-eating and omnivorous dinosaurs,by contrast, did not have such sharp, talon-like claws.They tended to be broader and more flattened, as theydid not need to kill. They were also stronger and morerugged because they were often put to many uses, fromwalking, to scraping or digging for food. Sometimesthese hoof-like claws were used in defence, as crudeweapons to slash out at attacking meat eaters.

"LEAPING LIZARDS"Caught in action, with theirteeth bared, these sparring

meat eaters show how they bestused their claws - for

vicious attack!

Flattenedclaw

43

SUPER SCYTHESTherizinosaurus (left) was one of the so-called“scythe lizards”. Its outsize claws look deadly,but they would have made awkward weapons.Perhaps they were used to rake up plants, slitopen termites’ nests – or even just for display.

Baryonyxclaw

Groove where hornycovering was attachedto claw

Rough bone forattachment of heavyclaw horn

ELEPHANT FEETThis huge claw came from a relative of Diplodocus

(pp. 14-21), called Apatosaurus. A plant eater, itwalked on four, pillar-like legs and had rounded

feet, like an elephant's. Most of its claws wereshort and hoof-like, except for the inside one

on the front foot, shown here. This clawmay have been used for digging, or

even for defence.

FISHING TACKLEThis hand claw was found only recentlyin Britain, along with other remains ofa meat-eating dinosaur (pp. 54-55). The

remarkable size and shape of the clawearned the newly discovered dino-

saur the nickname "Claws". Aflesh eater, it may have used

its highly curved clawlike a harpoon, to catch

fish for its dinner!

DINOSAURS, LIKE REPTILES and birds today, laid hard-shelledeggs. We know this because many fossilized dinosaur eggs havebeen found, some even containing small skeletons. Sometimesthe eggs have been found in nests, with remains of the parentdinosaurs nearby. Nests found complete with fossilized young

tell us that baby dinosaurs, like baby birds, would instinctivelystay in their nest, no matter what

happened to their mother. Severalnests found close together suggest

that some dinosaurs nested incolonies. It is perhaps surprising that dinosaur eggswere never very huge. If they were in proportion tothe size of some adult dinosaurs, the shells wouldhave been far too thick to hatch, and would nothave allowed enough oxygen to reach the creaturesgrowing inside.

Eggs and nests

DINOSAUR AND BIRDThe hatchling that wouldhave emerged from thedinosaur egg (right) wouldhave had lots of growing to dobefore it was an adult – far morethan a chick from a modern bird’segg, such as the quail egg (above).

A baby Maiasaura (p. 46)emerges from its egg

A HARD SHELLThis elongated egg

was part of the first evidence that

dinosaurs laid eggs.They laid their eggs on

land, just like lizards dotoday. The amphibians, from

which they evolved, had to laytheir eggs in water, where they hatched into

tadpoles. Reptiles, however, can lay their eggson land because the eggs have tough shellswith a private pond inside for the young to

develop safely. Laying eggs like this wasprobably one of the reasons why the dinosaurs

survived on Earth for so long.

Quailegg

Unidentifieddinosaur

egg

Textureddinosaureggshell

Cracks whichoccurred during

fossilization

Oviraptoregg

GROUND NESTER This model shows an Oviraptor

mother brooding its clutch of eggs. Its nest is scraped into

a mound, a design thatwould have stopped

the eggs from rollingaway and also given

some shelter. Likemany ground-nesting birds today, Oviraptormay have used her body heat toincubate the eggsuntil they hatched.

44

Nest in which eggs wereburied has turned intosandstone throughfossilization process

THE EGG THIEF?In the 1920s this fossilized nest, andmany more like it, was discovered inthe Gobi Desert of Mongolia andChina. For a long time, scientistsbelieved the nests belonged to thehorned, plant eating dinosaur,Protoceratops. When remains of anOviraptor were found on the fossil site,it was thought to have been there as ascavenger, stealing the eggs - the nameOviraptor means “egg thief”. Gradually,however, more and more Oviraptorremains were found. In the 1990sscientists finally realized that the nests and eggs belonged to Oviraptor,not Protoceratops.

46

THE NURSERYThis old illustration was drawn when the GobiDesert eggs were thought to be Protoceratops’.

It shows how people imagined a dinosaurnursery. There are baby Protoceratops at variousstages - some hatching, some taking their firststeps, some struggling to get out of the sand!

A BEAST EMERGESThis fossilized eggshell

(left) contains a hatchingduckbill dinosaur called

Maiasaura, or “good motherlizard”. It was found in the

1980s in Montana, USA, alongwith hundreds of other dinosaur

eggs and babies. It is shown here atlife-size - small enough to fit in anadult’s hand.

Nostril

Sauropodeggshell

fragments

Protoceratopseggshell

fragments

COARSE SHELLSThe coarse, pimply surface ofthese Protoceratops shell fragmentsis typical of many dinosaur eggs.

GIANT SHELLSThese fragments come from

large round eggs that were laidby huge sauropod dinosaurs like

Diplodocus (p. 14).

Birth and growthBECAUSE MOST OF the dinosaurswere so big, it is hard to imaginethem as going through babyand juvenile, as well as adultstages in their lives. Butrecent discoveries haveenabled us to piecetogether a little of theirearly lives. We knowthat dinosaur motherslaid their eggs inhollowed-out nests inthe ground (pp. 44-45).In some cases, tiny skeletonsof hatchlings have been foundinside the eggs. Colonies ofduckbill dinosaur nests havebeen found containing

skeletons of hatchlings. Their teeth are worn, indi-cating that the mother dinosaur would havebrought food back to the nest. Baby dinosaursprobably grew fast. In the case of sauropods,which moved in herds (p. 12), the youngstersprobably walked in the middle, protected bythe adults on the outside. Some dinosaurs,like the ceratopians, changed their bodilyproportions as they grew up.

Nostril

Flattened noseridge

Orbit (eye socket)

47

FIRST-HORNED FACEProtoceratops, or “first-horned face” was one

of the first ceratopians (p. 30). Small andsquat, Protoceratops was no longer

than 2 m (6 ft), and about the height of a large dog.

Lower jaw

Jaw joint

GROWN-UP DINOSAURAn adult Protoceratops skull displays

a very large bony frill at the back of thehead. This was an area for the attachment of

powerful jaw muscles. It also provided a displaystructure: the larger the frill, the larger and morepowerful the adult.

Area for attachment ofjaw muscles

Big frill for displayJuvenile Protoceratops skull

DINOSAUR KIDThis skull belonged to a juvenile Protoceratops.

As these dinosaurs grew, the shape of their skullschanged too. When compared to the adult skullbelow, you can see just how the proportions altered.Junior Protoceratops had a much lower nose ridge,for instance. The adult developed a higher ridge inorder to butt opponents.

Adult Protoceratops skull

Orbit (eye socket)

High nose ridge

Frill is quite short

48

A MASS EXTINCTIONMany other creatures died out at the time of the dinosaur extinction. Whatever happened seemed

to affect some creatures, but left others unscathed. Ammonites (above left), a type of shellfish,became extinct, as did the mosasaurs, plesiosaurs, and ichthyosaurs, groups of meat-eating

marine reptiles (above right). Sea crocodiles died out but the river crocodiles survived.The flying reptiles, pterosaurs, disappeared, but birds were unaffected.

Stony meteoritefragment

ROCKSFROM SPACEA likely reason for the suddenextinction is that a massive meteoritefrom space collided with the Earth.This would have been catastrophic,causing a huge steam and dustcloud which darkened theEarth for a long time,killing off the plantsand the animalsthat fed onthem.

Ironmeteoritefragment

Shaft of ischium bentforward after repair

Iguanodon ischium(hip bone)

Fossilizedammonite

POISONOUS BITEIt has been suggested

that dinosaurs died outbecause they ate newkinds of poisonous

plants, such as deadlynightshade, that

started growing on theEarth.

Death of the dinosaursDINOSAURS DISAPPEARED from the Earth quite suddenly, and why thishappened is still a mystery. Around 70 million years ago, the dinosaurs ruledthe Earth. Yet about five million years later, they had all died out, perhapsonly in a matter of months. Scientists have put forward various theories toexplain their sudden extinction, but many ignore one vital point: dinosaurswere only one of a whole range of creatures that died out at the same time,including all the swimming and flying reptiles. So any theory to explaindinosaur extinction must explain the disappearance of these groups as well.The theories are numerous: some people think thatsmall mammals ate all the dinosaur eggs. This isvery unlikely - for how would it account for theextinction of other species that disappeared at

the same time? Others believe that dinosaurssimply grew tired of life on Earth and

died of boredom!

49

Vertebralspine

THE BEGINNINGOF THE END

A Tyrannosaurus rexis shown fleeing in

terror as a meteor hitsthe Earth. The impact

would have had an effectrather like that of a massive

nuclear war. Dense black clouds of dust andsoot would have cut out the sun for months.

A GROWTHDinosaurs could contract cancer. This section of backbone

belonged to a hadrosaur, and shows a swollen areawhich was a cancerous tumour in the bone.

Point offracture

Vertebralbody

Swollen area oftumour growth

BROKEN BONEDuring their reign, dinosaurs were not immune to diseases

and accidents. The Iguanodon hip bone (above), shows a fracturethat healed itself during the creature's lifetime.

Thickening ofbone around break

Section ofhadrosaur backbone

Dinosaur or bird?

BIRDS OF A FEATHERArchaeopteryx, seen here

preening on a ginkgo branch(pp. 10-11), had severaldistinctly un-birdlikefeatures. It had a long tailwith bones down themiddle, claws on its wings,and teeth. Its wings weredesigned for flight, but it isunlikely that Archaeopteryxcould have flown as wellas modern birds.

BAVARIAN BIRDDiscovered in Germany, this Archaeopteryx

fossil is the best example found to date. It is preserved in fine-grained Bavarian

limestone. You can clearly make out thefeathers of the wing and tail, the

twisted neck and head, and even the claws on its wings.

ARE BIRDS THE DESCENDANTS of the dinosaurs?The debate first began with the discovery of afossil bird, Archaeopteryx. It lived 150 millionyears ago, alongside the dinosaurs. It had

feathers, like all birds, but also reptilian features,such as teeth. Could this be the missing link

between dinosaurs and birds? Archaeopteryx wasshown to share over 20 features with meat-eatingdinosaurs such as Coelophysis, right. One gap inthe evidence was the lack of any dinosaur fossilswith a wishbone: birds have a well-developed

one that helps to keep the wing joint inposition. But now we know that several

dinosaurs - mainly meat eaters - did have a wishbone. More dramatically, fossil

hunters in China have unearthed feather traces belonging to bird-like dinosaurs such as

Caudipteryx and Sinornithosaurus. Some scientistsalso think theropods in North America, including

Bambiraptor and Troodon, were feathered, but othersremain sceptical about the dinosaur-bird link.

Archaeopteryx

50

Long tail

Claws on wing

Featherimpressions

Long, bony tail

FOSSIL FABLEThis complete fossil of Coelophysis, a small meat-eatingdinosaur, was found at Ghost Ranch in Texas, USA, alongwith many others. It lived right at the beginning of thedinosaur age. Lightly built and agile, it had three strongclawed fingers on each hand - a feature in commonwith Archaeopteryx. In its belly you cansee bones that are actually the remainsof some young of the samespecies. So Coelophysis mayhave been a cannibal.

BAMBIRAPTOR IN ACTIONA birdlike dinosaur called Bambiraptorwas discovered in Montana in 1994. It

could not fly, but musthave been a fast

runner, able tohunt frogs and

small mammals.It was probably

covered withdowny feathersthat kept in its

body heat.

BAMBI’S BONESBambiraptor had a wishbone and some of its bones

had air sacs, just like the bones of a bird. The dinosauralso had large eye sockets and a bigger brain cavity

for its size than any other dinosaur. However, its deepsnout and large teeth were not at all birdlike.

AN EXCITING CHINESE FINDCaudipteryx was a turkey-sized dinosaur discoveredin China. Its teeth and bones, especially its forward-pointing pubic bone, indicate that Caudipteryx was a dinosaur. However, it had a beak, feathers, andshort tail. No one really knows what colourCaudipteryx’s feathers were. It is possible thatthey were brightly coloured and used forspectacular mating displays, as well askeeping the dinosaur warm.

51

Sharp, predatoryteeth

Hipregion

Coelophysisskeleton

Remains of young Coelophysisin belly

Bambiraptorskeleton

Caudipteryx

BambiraptorA wrist joint like a bird’s wouldhave enabled Bambiraptor to foldits hands as a bird folds its wings

52

How to find a dinosaurHOW DO SCIENTISTS go about discover-

ing dinosaur remains? Because thedinosaurs became fossilized in thefirst place by being buried in sand,or mud, we know that their fossilscan only be found in sedimentaryrock - rock that has been built upin layers over the years. Fossilsare often found by accident, bybuilders, or quarrymen digginginto the ground. Fossil collec-tors may set out deliberatelyto search an area that isthought to be rich in fossils.Sometimes a large and

highly organized scientific expedition is under-taken, based on detailed research. Whatever themethod of discovery, careful preparation mustbe done if the find is to be recovered success-

fully. Records needto be made of the

exact position ofthe find, and theright tools areneeded to ensure thatthe fossils are extractedfrom the site and returnedto the laboratory withoutbeing damaged.

HAMMERSA variety of hammers areused by palaeontologists(fossil experts) in the field.The geological hammers shownhere are good at splitting fossil-bearing rock.

Straight-headedhammer for splitting

hard rock

Curved-headedbrick hammer for

breaking up andclearing softer

rocks such as clays

Rock sawfor cutting

throughrock

Cloth bags

TAKING NOTEOn a dig, palaeontologists always recorddetails of a find, and draw a map of

the site. Broken fragments andsamples of rock are col-

lected in bags andanalysed laterback in the

laboratory.

PROTECTIVE GEARIt is essential to wear

proper protective clothingwhile on a fossil dig. Gloves are neededwhere heavy hammering and chisellingis to be done, as are goggles to prevent

splinters of rock from damaging the eyes.A hard hat is also advisable, especially

if work is being done near cliffs.

Gloves

THE FIND!Discoveries of fossil dinosaursare rare, and best tackled by ateam of experienced people.

DUTCH DISCOVERYThe jaws of the mighty sea lizard Mosasaurus werediscovered deep in a chalk mine near Maastricht inHolland in 1770. This etching shows the team ofdiscoverers working by torchlight.

53

Hard hat andprotective goggles

Pointed chisels

EXPOSING A FINDWhen the rock inwhich the fossil is

embedded is veryhard, a heavy hammerand chisels are needed.This lump hammer isused to drive chisels intothe rock. It is useful tohave a wide variety ofchisels for getting intoawkward corners.

Clipboard withdrawing of thesite, and notebookwith field notes

Flat chisels

Plasticbags

Lump hammer

RAW MATERIALSTo make a plaster jacket, the plaster

is mixed with water to make a paste,then the scrim is dipped into it. A

layer of wet tissue paper is used tocover the rock and fossil before

plaster and scrim is applied. Thisprevents the plaster sticking to

the rock and fossil.

Hard paintbrush

Roll of plasterer's scrim(open-weave fabric),and plaster of Paris

Polyurethanefoam jacket

FOAM JACKETSometimes fossils are protected by

a polyurethane foam jacket. Thefossil is first wrapped in foil, then

the chemicals to make the foam are pouredover it. The foam expands and surrounds the

fossil, which can then be moved safely.CAUTION: Foam gives off toxic gases as it

is mixed, and is not recommended for useexcept by professionals.

PROTECTING THE FINDA palaeontologist on a digcarefully covers a fossil witha plaster jacket.

Aluminium foilcovers fossil

Baryonyx ribs encased in plaster jacket

Softpaintbrush

POT AND BRUSHESBrushes are used to clearaway dust while rock isbeing chipped awayaround fossils. As a fossilis exposed, it is oftenpainted with hardener,like glue, to secure anyloose fragments.

Pot of glue

RIBS IN A JACKETWhen fossils are partly

exposed, they are sometimesencased in plaster jackets to

protect them for transportationback to the laboratory. Two

ribs of the recently discovereddinosaur Baryonyx can be seen in

this jacket (pp. 54-55).

ON DISPLAYMuseums often display fossilreplicas, cast from moulds ofthe real, delicate fossils. This

Barosaurus reproduction isbeing erected in the AmericanMuseum of Natural History.Not all scientists agree that

Barosaurus could rear like this.

Making a modelMany museums display cutaway reconstructions of dinosaurs, like the one below. The startingpoint is a scale drawing that details how the bones and muscles fitted together. Based on this, anarmature (framework) is built from wire and wood. A sculptor shapes modelling clay around the

armature, adding in details such as bones and skin texture. The clay modelis used to create a rubber mould, so that a resinversion can be cast. Finally, the cast is handpaintedand airbrushed.

54

Preliminary sketch

Finished claymodel

Rubber mould

Painted andfinished cast

Wire and woodarmature

AFTER THE HARD work ofexcavation, the preciousfossils are taken back to the laboratory forpreparation, study, anddisplay. This whole process isa lengthy one. First, the fossilremains need to be carefullyremoved from their protectivejackets (p. 53). Then, the remainingrock or earth in which the fossil was

originally buried has to be cleaned away.Chisels are used on hard pieces of rock, or

more delicate power-driven tools (like dentists’drills), for detailed work. Sometimes chemicals

are used to dissolve away the surplus rock. Thecleaned bones are then carefully studied in orderto understand how they fitted together, andtherefore how the dinosaur lived. Some tell-taleclues are to be found on the actual surface ofbones, because muscles sometimes leave clearmarks where they were attached. These marks canbe used to reconstruct dinosaur muscles, or flesh.

DIGITAL DINOSAURSComputers now create superb 3-Dreconstructions of dinosaurs andother prehistoric creatures, suchas this pareiasaur (right). Digitalmodels can be viewed from allangles and even shown in motion.

How to rebuild a dinosaur Iguanodon foot bone

Cartilage cap of ankle joint

Ligament scars

CLUES FROM THE BONEThis foot bone from Iguanodonprovides many clues of muscle

attachment during life. At theupper left end its surface is

roughened for attachmentof cartilage (gristle) of theankle joint, and along its

length are ligamentscars for attachmentto other bones. The

rough area at thebottom of the bone

is a cartilage jointsurface for the

middle toe .

Cartilage surfaceof joint for toe

55

IN DEATH THROESBaryonyx is shown here as it lookedafter it died. It sank to the bottomof a lake where it graduallybecame fossilized. Such arealistic model shows howthe skills of the scientistand model-maker can bebrought together to greateffect. The way thatthe dinosaur was lyingwas worked out fromthe position in whichthe bones were found.

Model of Baryonyx as it looked after it died

A NECK BONEThis neck bonebelonged to thenewly discovered dinosaurBaryonyx, seen reconstructedbelow. The bone has avery complicated shape andwas buried in very hard rock,so it took a very long time toprepare. The faint scratchesthat can be seen are whererock remains to be cleared.

AN ACID BATHSometimes, in laboratories,vats of acid are used to dis-solve away rock from fossilswithout damaging them. Thechemicals used in this processcan be very dangerous, so protect-ive clothing must always be wornwhen lowering the fossil into the vat.

Faintscratches

Baryonyx neckvertebra

A LOAD OF OLD BONESDuring the 19th century, when dinosaurs had just beendiscovered, (pp. 8-9), the sculptor Benjamin WaterhouseHawkins built models of dinosaurs first in Britain,then in the United States. This shows his work-

shop in New York.

56

The timescaleIT IS INCREDIBLE TO THINK that animals andplants have lived on this Earth for over 700million years. During this time a bewilderingvariety has come and gone. The first dino-saurs appeared about 210 million years ago(mya) at the end of what is known as theTriassic Period. They roamed the Earththroughout the Jurassic Period until 64 millionyears ago, right at the end of the Cretaceous Period.During the millions of years of life on Earth, theworld has changed enormously: continents havemoved, sea levels have altered, climates havechanged, creatures have become extinct. If we lookat fossils of creatures that lived before, during, andafter the dinosaur age, we can see how some thingshave changed, and some have remained much the same.

At the time when the dinosaurs appeared, none of the countries of theworld existed as we know them - the world consisted of one hugelandmass called Pangaea.

IN THE MISTS OF TIMEThis is what the world may havelooked like during the dinosaur age.Dinosaurs lived through three periodsof time: the Triassic, from 230 to 195mya, the Jurassic, from 195 to 141 mya,and the Cretaceous, from 141 to 65 mya.

Small spikyteeth

A BEETLEBeetles are a group with a very longhistory, and were probably the prey

of early reptiles andamphibians, just asthey are today.

260 mya:AMPHIBIANAmphibians lived before and during thedinosaur age, and are still with us today.Frogs, for instance, are amphibians. Theycan breathe andmove on land,but have tolay their eggsin water(p. 44).

SCORPION STORYLiving scorpionsbelong to an ancientgroup which datesback about 400million years.

230 mya: DIICTODONSquat andpig-shaped,the owner ofthis mammal-likereptile skull ate plants andlived during the early Triassic Period.

230 mya: COELACANTH FISHThe earliest known coelacanth appeared390 million years ago. They werethought to be extinct, butrecently many living coela-

canths have been discovered.

Spaces forjaw muscles

230 mya:PROCOLOPHONThis is the skull of a smallearly reptile which fed onroots and tubers.

LIVING FOSSILThis lungfish has

fossil relatives whichdate back 390

million years.

TRILOBITEThis creature lived onthe sea bed andscuttled around onsharp, spiny legs.Although abundantin the early oceans, itwas extinct longbefore the firstdinosaurs appeared.

260 mya:EARLY REPTILEThis is the underside of theskull of an early lizard-likereptile, called Captorhinus. Itmay have eaten smallinsects and snails with itssmall spiky teeth.

57

200 mya:MEGAZOSTRODONThis furry model isbased on a tinyskeleton that wasfound a few yearsago. It was one ofthe earliest truemammals, and livedalongside the earlydinosaurs.

205 mya: MASSETOGNATHUS

The last mammal-like reptiles that appeared just before the earlydinosaurs were large and quite dog-like in appearance. Mammal-likereptiles became extinct when the dinosaurs appeared, but smaller,

rodent-like mammalssurvived.

Eye socket

200 mya: ICHTHYOSAURIchthyosaurs were swimming reptiles which flourishedthroughout the dinosaur age. This paddle - once alimb - would have been used by the animal topropel itself along in the water.Ichthyosaurs had long, narrow,pointed snouts.

Long narrowsnout

200 mya: CROCODILE

The shape of a crocodile skullhas not changed very much over

the years. Having a long snout linedwith teeth is one of the best ways of

catching swimming prey. The snout on thiscrocodile is particularly narrow, which

suggests that it must have been verypartial to fish.

The story continues...

210 mya: RIOJASUCHUS

This skull belonged to an immediate predecessor ofthe early dinosaurs, one of the thecodontian or "socket

toothed" reptiles. It was built like a long-legged crocodile,and had powerful teeth and jaws.

Two Thecodontosaurusfeeding

200 mya:THECODONTOSAURUSThis fragment of jawbelonged to an early dinosaur.Most early dinosaur fossilsare poorly preserved.

STAYING POWERCrocodiles lived before, duringand after the reign of the dinosaurs,and are still around today. Beingaggressive river-dwellingpredators obviously suitsthem very well.

EARLY DAYSThecodontosaurus could eat both

plants and meat (p. 23). Oneof these two is feeding oncycads, while the other isabout to pounceon a lizard.

58

160 mya: CROCODILECrocodile scutes, or plates,like this square bony one areoften found in rocks thatalso yield dinosaur remains.This suggests that croc-odiles may have scavengeddinosaur carcasses.

155 mya: PLESIOSAUR

This tooth belonged to aplesiosaur, a fierce predatorymarine reptile, contemporarywith ichthyosaurs (p. 57). Theyflourished in the sea during theJurassic Period.

Modern dragonfly

Fossil dragonfly140 mya:

DATED DRAGONFLYDragonflies can be called "livingfossils": they were flying in theskies 320 million years ago, andstill exist today.

147 mya: SPHENODONTID LIZARDLizard-like reptiles such as this

specimen have a very long history. Theylived throughout the reign of the dinosaurs.

140 mya: GRYODUSMany types of bony fish like this one lived atthe same time as the dinosaurs. Most werefossilized in fine lake sediments, so arepreserved in great detail.

145 mya: PTERODACTYLUSFlying reptiles called pterosaursflew in the skies while thedinosaurs ruled the land. Somewere the size of sparrows; otherswere as big as small aircraft. Thelarger ones would have swoopeddown to catch fish in the waters,while smaller ones, like thisPterodactylus (right), would havecaught insects in the air.

DAWN OF THE BIRDSThe first birds appeared in the late JurassicPeriod - about 150 mya. But they did not comeinto their own and dominate the skies untilthe pterosaurs became extinct (at the same time asthe dinosaurs).

Grey plover

140 mya: KING CRABKing crabs are onlyremotely relatedto crabs. Theyhave been aroundsince before thedinosaur age, andstill live today.

59

120 mya:CROCODILE

The crocodile that owned thisskull (right) lived in the earlyCretaceous Period.

Dryosaurus femur

136 mya: DRYOSAURUS

This femur (thigh bone)belonged to a small,fast-moving, plant-eating dinosaur.It used its speedto flee fiercepredators.

120 mya: LIZARD'S JAW

This fragment of jaw came from alizard like the sphenodontid preservedin rock, above left. Fragments like thisare found more often thancomplete specimens.

Water moccasin snake

120 mya: TEETHThese fierce-lookingstumpy crocodile teeth arepreserved from 120millionyears ago,but arevery like the teeth thatbelong toliving crocodiles today..

120 mya: SCUTE

Part of a crocodile's bony armour, this scute comesfrom a crocodile that lived during theCretaceous Period.

110 mya:GASTROPOD

Many different snails lived duringthe dinosaur age.

115 mya: IGUANODONThis is a tail bone from Iguanodon,a plant-eating dinosaur (pp. 8-9).Iguanodon lived only in theCretaceous Period.

The story continues...

SNAKES ON THE SCENESlithering snakes arrived on thescene in the late Cretaceous Period.They are like modifiedlegless lizards.

COME FLY...In the Jurassic Period, a sky scene at dawn ordusk would have been crowded with pterosaursdarting through the air catching prey.Their place is taken today by birdsthat feed on the wing: swifts,housemartins, andswallows.

Cockroach

THE GREAT SURVIVORThe cockroach is one of Nature's greatsurvivors. Cockroaches have lived onEarth since long before the dinosaur age,and, judging by their success at living inhuman environments, they seem set tosurvive well into the future.

60

The end of an eraAS THE CRETACEOUS PERIOD drew to a close,the dinosaurs became gradually less numerous,until eventually they disappeared altogether. Atthe same time changes were also taking place in theEarth's landscape. The continents became separatedby wide stretches of sea. Sea levels rose also, flooding muchof the low-lying land where many types of dinosaur lived. Manygroups of sea animals became extinct. Instead of being warmall the time, the climate began to become more variable, orseasonal. The types of plants living at the timealso changed: flowering plants becameincreasingly important. As the dinosaursdied out, they made way for a newruling group on the Earth:the mammals.

Turtle shell

NOT LONG TO LIVEThe formidable mosasaurs only lived

at the end of the Cretaceous Period,and became extinct

alongside the dinosaurs.

95 mya: TURTLE

This turtle shell is a relic from theCretaceous Period. Turtles were anothergroup that flourished instead ofbecoming extinct.

100 mya: ICHTHYOSAUREmbedded in rock, these sharp, pointedteeth belonged to an ichthyosaur (p. 57).Marine reptiles like this all becameextinct at the same time asthe dinosaurs.

70 mya:MOSASAUR

This giant marinelizard used itslarge pointedteeth to crackopen shells of

animals such asammonites

(p. 48).

90 mya:ALBERTOSAURUS

The owner of this toe bone was a large meat-eatingdinosaur. Few of these meat eaters survived up tothe end of the dinosaur age.

75 mya: CRAB

Closely relatedto the lobsters,crabs did not

suffer extinction(p. 58).

Crab

Scales

85 mya: MARSUPIAL

This jaw bone belonged to apouched mammal (like a kangaroo). Nowfound only in Australia, marsupials livedalongside the dinosaurs, and were able toevolve rapidly after they

disappeared.90 mya:

BONY FISHBony ray-finned fish were anothergroup that suffered very little

damage during the"great extinction".

100 mya:LOBSTERSome marine groups, like the lobsters,were little affected by the mass extinctionthat happened at the end of the CretaceousPeriod. Why some groups were affected, and othersnot, is to this day a great mystery.

100 mya: LEAF

Broad leaves like this one are typicalof flowering plants that appearedduring the Cretaceous Period.

RED HERRING?The bony fish we arefamiliar with today arevery like those that livedin the late Cretaceous.

50 mya:EARLY HORSEHorses appeared soon after thedinosaurs became extinct, and soonthere were many different types ofhorse grazing upon the new plantsand grasses that were growing.Early horses had toes, not hooves,on their feet.

40 mya: LIZARDThis jaw belonged to aland lizard. Although allthe giant marine lizards likemosasaurs (pp. 48 and 60)became extinct with thedinosaurs, the small land-living ones wereunaffected.

Red rose

FLOWER POWERThe flowering plants that appearedearly in the Cretaceous Period soonbegin to dominate the plant world.

THE BUZZING BEGINSBrightly coloured flowers and flower scents seemed toherald the arrival of butterflies and bees. Attracted bythe colours and scents of the flowers, butterflies, bees,and other insects carried pollen from one to the other, justlike they do today.

Hyracotherium(early horse) skull

Cricket

55 mya: TURTLE SKULL

Spider

35 mya:EARLY RODENTGnawing animals like rats andmice did not exist until wellafter the dinosaurs died, andare thriving today.

35 mya:NSECTS IN AMBER

This cricket andspider have beenperfectly preserved

from millions of yearsago, because they becametrapped in amber (fossilized

resin) exuding frompine trees.

Early rodent skull

25 mya: SHARK TOOTH

Sharks have beenaround for 400million years,and havechangedvery little.

A BRACHIOPODOne of the longest survivors of all

groups in nature, brachiopods,or "lampshells", found todayare little changed from types

found in rocks 500million years old.

Human skull

TURTLE TALETurtles andtortoises belong toa group of reptilesthat have changedvery little in appearancesince their origins 200million years ago.

Hawksbill turtle 1 mya: HOMO ERECTUSHuman beings were one of the lastspecies to arrive on the ever-changing scene on Earth. Earlyspecies of humans date backa mere one million years(64 million years afterthe last dinosaur died).In this "short" periodof time, people haverisen to dominatemost of the land,and arebeginning tohave a notice-able effecton theenvironment.

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BRONTOSAURUS BLUNDERSScientists do the best they can with the evidence available, but early models

of Apatosaurus, originally called Brontosaurus, were based on a mix-up. Itsskeleton had been dug up but it lacked a skull, and its bones became

muddled up with another sauropod, Camarasaurus. Museum reconstructionsshowed “Brontosaurus” with a short, round skull until the 1980s, when its

real skull was found, proving to be very like the skull of Diplodocus (p. 22).

Myths and legendsWHEN DINOSAUR BONES were first discovered, people found

it hard to believe that these creatures had actually lived onEarth. The giant dinosaurs became linked with terrifyingmonsters in peoples' minds. Because so little was known

about them, many mistakes were made at the beginning.Dinosaur bones were put together in the wrong way (p. 8),or even mixed up with otherbones. Today, misconceptionsabout dinosaurs are just ascommon. Visitors to museumsoften think that the dinosaurswalked around looking likeliving skeletons! Politiciansand commentators sometimesunfairly use dinosaurs todescribe something that isold-fashioned, out of date,useless, or inefficient. It iscommon to think that dino-

saurs were animals that were big, dull, stupid, and headed forextinction because they were poorly designed to cope withthe world in which they lived. In fact, nothing could be furtherfrom the truth. Dinosaurs were among the most elegant andsophisticated animals that the Earth has ever seen, and sur-vived for nearly 150 million years - 75 times longer than

humans have lived on Earth.

DINOSAURS IN THE TREESWhen Hypsilophodon, a small, agile, plant-eating

dinosaur, was first discovered, it was thought to livein trees. Indeed, it was believed to be the dinosaur

equivalent of a tree kangaroo that lives in Papua NewGuinea. Scientists thought its long tail helped it to

balance in the trees, while special sharp toes on itsfeet helped it to cling to branches. Now this theory

has been proved wrong. In fact, Hypsilophodonwas a ground-dwelling dinosaur that used its

stiff tail as a stabilizer while running.

A WATERY ENDA common mistake is to believe that dinosaurswere sea monsters, possibly still lurking in theocean depths. In fact, no dinosaur was purelysea living. The sea reptiles that shared thedinosaur world were mostly plesiosaursand ichthyosaurs.

DINOSAUR DRAGONThe winged dragon of mythology looks very

like some dinosaurs, except for the wings. Somepeople see dragons and dinosaurs as being one

and the same. But the big difference is thatdragons never existed!

62

Two Hypsilophodon dinosaursperched in a tree

Grasping hand tohold branch

Special grasping toes

Balancing tail

CHINESE DRAGONSThe mythical dragon is an

important symbol in Chineseculture, and it seems likely that it originated from

the discovery of dinosaur remains. The Chinese havebeen collecting dinosaur fossils for over 2,000 years,

but referring to them as dragon bones. Even today"dragons' teeth" which are mostly fossil dino-

saur teeth are collected and ground intopowders for use as medicines, for they are

thought to have healing properties.

DINOSAURS AND CAVE DWELLERSSome films and cartoons have given the

impression that dinosaurs shared the Earthwith early people. In fact, dinosaurs became

extinct 64 million years before the first peopleever appeared on the Earth!

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Did you know?AMAZING FACTS

Iguanodon is one of the mostcommon dinosaurs. In one

location, between 1878–81, coal minersin Belgium dug up over 39Iguanodon skeletons.

One of the

rarest dinosaursknown is Baryonyx.So far, only onespecimen has beenfound. It includes a 30-cm (6-in)-long thumb claw.

Dinosaur fossils have beendiscovered in rocks from the

Triassic Period. One of the earliestdinosaurs may have been Eoraptor, whichwas discovered in Argentina in 1991. Itsname means “dawn (or early) plundererlizard”, because this meat-eater lived about228 million years ago, at the beginning ofthe dinosaur era.

Remains of dinosaurs have beendiscovered in Madagascar, Africa,

which may be older than Eoraptor, ataround 234 million years old. However, the remains are in poor condition andscientists are still debating the find.

The earliest-known carnosaur isPiatnitzkysaurus, from the

Jurassic Period.

The first dinosaur named was thecarnosaur, Megalosaurus, in 1824.

The name ornithomimid means“bird-mimic reptile” because

scientists think these dinosaurs werebuilt like flightless, long-legged birdssuch as ostriches.

All that scientists knew of Troodonfor several years was a single tooth

– the name “troodontid” means“wounding tooth”.

Troodon is the best-knowntroodontid. It had large eyes and

a relatively large brain for its body size,giving it the reputation of being one of themost intelligent dinosaurs and a successfulhunter. Scientists base this theory on thesimilarity of the optic nerve channels andbrain cases of fossils with those of modernpredatory creatures.

Troodontid fossils are rare, partlybecause their thin bones were not

easily preserved.

Dromaeosaurid means “runninglizard” and these small, aggressive

hunters were probably both swift andlethal, with their blade-like fangs,clawed hands, and hugeswitchblade claws ontheir secondtoes.

Fossilsof the

small plant-eater Protoceratops are soabundant in the Gobi Desert in Mongolia,that fossil-hunting palaeontologists therecall it the “sheep of the Gobi”.

A tangled fossil found in the GobiDesert in 1971 shows a

Protoceratops and a Velociraptor fighting.The Velociraptor had grasped the plant-eater’s snout while kicking its throat. TheProtoceratops had gripped its attacker’s armin its strong beak. The animals may havedied from their wounds or been killed by a fall of sand from a nearby dune.

Scientists used to think that theankylosaurs were the only

armoured dinosaurs until the discovery ofan armoured sauropod, Saltasaurus. Itsarmour consisted of large bony platescovered by smaller, bony nodules, andprobably covered its back and sides.

Coprolites – preserved dung –contain the remains of what

dinoaurs ate, such as bone fragments, fishscales, or the remains of plants. Scientistscan study them to find out about dinosaur diets.

A dinosaur egg can only be firmlyidentified if an embryo is preserved

in it. So far, this has only been possiblewith Troodon, Hypacrosaurus, Maiasaura,Oviraptor and, recently, a titanosaur (seenext page).

The first complete titanosaurskeleton was found in Madagascar

in July 2001. Titanosaurs grew to around 15 m (50 ft) long but their bones wererelatively light, so few have survived.

Tyrannosaurus had the reputation of being the largest meat-eater

for many years, but lost out in 1993 when an even larger meat-eater(Giganotosaurus carolinii) was discovered in southern Argentina.

Giganotosaurus is thought to havebeen as heavy as 125 people, with

a head twice the size of that of Allosaurus.

Dinosaurfootprints

are far morecommon than fossildinosaur bones.They are often giventheir own scientificnames because it isdifficult to tell whichparticular animal madea particular footprint.

Few dinosaurtracks show the

marks of a tail, whichsuggests that dinosaurswalked with their tailsheld off the ground.

Baryonyx claw

Troodon

Large eyesabsorb morelight, improvingnight vision

Fossilized skin of Saltasaurus

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QHow many types of dinosaur are there?

ASo far, about 700 species ofdinosaur have been named.

However, half of these are based onincomplete skeletons, so some maynot be separate species. About 540dinosaur genera have been named.Of this number, about 300 areconsidered to be valid genera. Mostgenera contain only one species, butsome have more. Some scientistsbelieve that there may be 800 or sodinosaur genera still to be discovered.

QHow are dinosaurs named?

ADinosaurs may be named after afeature of their bodies (such as

Triceratops, meaning three-horned face), the place where they were found (such asArgentinosaurus), or after a person involvedin the discovery, such as Herrerasaurus

(Herrera’s lizard). An animal name usuallyconsists of the genus and the species name.For example, the biological name forhumans is Homo (genus) sapiens (species).

QHow did dinosaurs communicate?

AScientists believe that dinosaursprobably communicated through

sound and visual displays. The chamberedcrests on the heads of some dinosaurs, suchas Parasaurolophus, may have amplifiedgrunts or calls. It is thought that forest-living dinosaurs made high-pitched soundsthat carried through the trees. Those thatlived on the plains may have made low-pitched sounds that would carry well along the ground. Visualdisplays could have included posturing, such as pawing the ground or shaking the head.

QWeredinosaurs warm-

or cold-blooded?

AThe debate still ragesabout whether dinosaurs

were warm-blooded, likemammals, or cold-blooded,like reptiles. Swift and agilepredators, such asDeinonychus, would indicate awarm-blooded mode of life.Also, some dinosaurs havenow been found with feathers,and only warm-bloodedanimals would need suchinsulation. However, somedinosaurs, such as Stegosaurus,had plates on their backs,possibly to collect heat fromthe Sun, which suggests theywere cold-blooded. In 2000, research was published on the discovery of the first-everfossilized dinosaur heart (in1993). Many scientists disputethe findings. However, theresearch suggests that theheart was similar to those ofbirds and different from thoseof modern-day reptiles, sosome dinosaurs at least wereprobably warm-blooded.

QWhat colour were thedinosaurs?

APalaeontologists do notknow for sure, but they

think that most dinosaurs mayhave been as brightly colouredas modern-day reptiles (suchas snakes and lizards) andbirds. Some may have hadpatterned skin to help themhide in vegetation. Others mayhave had bright warningcolours to scare off predatorsor as a kind of display to helpthem find a mate.

QWho found thousands of dinosaur eggs?

AIn 1997, a group of Argentinianand American scientists

discovered thousands of grapefruit-sized rocks littering a dry, barrenarea in Patagonia, South America.As they neared the site, theyrealized the “rocks” were fossilizeddinosaur eggs. Some of the eggs

contained embryos, so the scientistswere able to work out that the unborn

babies were probably titanosaurs. Themothers would have returned to the same

nesting grounds each year.

Titanosaur eggs

QUESTIONS AND ANSWERS

BIGGEST DINOSAURSeismosaurus (“earth-shaking lizard”)probably measured around 34 m (110 ft)and weighed up to 30 tonnes (29.5 tons).Some scientists believe Argentinosauruswas ever larger overall, weighing 50tonnes (49 tons). However, skeletons of both are incomplete.

BIGGEST MEAT-EATERTheropods Giganotosaurus (“huge lizard”)and Carcharodontosaurus (“shark-toothedlizard”) were both nearly 14 m (46 ft) long.

BIGGEST HEADIncluding its head shield, the head ofceratopian Torosaurus measured 2.8 m (9 ft)long – longer than a saloon car.

LONGEST NECKThe neck of Mamenchisaurus measured upto 9.8 m (32 ft) and contained 19 vertebrae,making up almost half of the animal’s total body length.

SMALLEST BRAINStegosaurus had the smallest brain of anyknown dinosaur. It weighed about 70 g(2.5 oz) and was the size of a walnut.

LONGEST DINOSAUR NAMEMicropachycephalosaurus

SHORTEST DINOSAUR NAMEMinmi

Record Breakers

Psittacosaurus, meaning

“parrot lizard”

Stegosaurus

Classification of dinosaursALL LIVING THINGS ARE CLASSIFIED into different groups, according to their common features. The classification of dinosaurs, however, is controversial and continually revised as new discoveries are made and existing evidence is reinterpreted. In this chart, dinosaurs are subdivided into two main groups – Saurischia (lizard-hipped dinosaurs) and Ornithischia (bird-hipped dinosaurs). Each group is then subdivided into the levels of families (with names ending in “-idae”), genera (indicated in the chart below in italics), and species. Birds (Aves) are now generally considered to be the descendants of the dinosaurs.

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ORNITHISCHIA

ORNITHOPODA CERATOPIA PACHYCEPHALOSAURIA ScelidosaurusScutellosaurus

HuayangosauridaeStegosauridae

AnkylosauridaeNodosauridae

MARGINOCEPHALIA

STEGOSAURIA ANKYLOSAURIA

CERAPODA THYREOPHORA

Lesothosaurus

Pisanosaurus

Hypsilophodon,an ornithischian

Lesothosaurus, a primitive ornithischian

Stegoceras, apachycephalosaur

Triceratops,a ceratopian

Scelidosaurus,a thyreophoran

Edmontonia,a nodosaurid

CeratopidaeProtoceratopidaePsittacosauridae

Iguanodon,an ornithopod

CamptosauridaeDryosauridae

HadrosauridaeHeterodontosauridaeHypsilophodontidae

Iguanodontidae

ChaoyoungosauridaeHomalocephalidae

Pachycephalosauridae

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DINOSAURIA

SAURISCHIA

THEROPODA SAUROPODOMORPHA

HERRERASAURIA

CERATOSAURIA TETANURAE PROSAUROPODA SAUROPODA

Abelisauridae Alvarezsauridae Ceratosauridae Coelophysidae Noasauridae

BarapasauridaeBrachiosauridaeCamarasauridae

CetiosauridaeDicraeosauridae

DiplodocidaeEuhelopodidaeTitanosauridae

Vulcanodontidae

AnchisauridaeBlikanasauridae

MelanorosauridaePlateosauridae

Yunnanosauridae

CARNOSAURIA COELUROSAURIA AVES DEINONYCHOSAURIA

Halticosauridae

ORNITHOMIMOSAURIA OVIRAPTOROSAURIA

AllosauridaeAublysodontidae

BaryonychidaeDryptosauridae

ItemiridaeMegalosauridaeSpinosauridae

TorvosauridaeTyrannosauridae

AvimimidaeCoeluridae

Compsognathidae

DromaeosauridaeTherizinosauridae

Troodontidae

Archaeopterygidae DeinocheiridaeGarudimimidaeOrnithomimidae

CaenagnathidaeIngeniidae

Oviraptoridae

Bird-hipped dinosaurs

Lizard-hipped dinosaurs

Melanorosaurus, a sauropod

Herrerasaurus,an early theropod

Plateosaurus, a prosauropodCoelophysis, a theropod

Allosaurus,a tetanuran

Compsognathus, a coelurosaur

Gallimimus, an ornithomimid

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Find out more

GO FOSSIL HUNTINGA great deal of research is madebefore any organized fossil-hunting expeditions bypalaeontologists. Even so, someimportant dinosaur discoverieshave been made by amateurfossil-hunters where fossil-bearing rocks have beenexposed. Eroding cliffs are the best places to find fossils,especially on seashores. Beforestarting any such search,collectors must make sure theyget permission to visit a site ifnecessary. Care must also betaken at coastal sites to stayaway from overhangsand watch for theincoming tide.

Full-sized mechanical model of anallosaur, used for close-up shots inThe Lost World in conjunctionwith computer-generated images

SEE A FILM!Recent films and television programmes use computer-generated imagery (in which many of the visuals arecreated and animated by computer software) to portray

dinosaurs. Jurassic Park was the first film to employpalaeontologists as advisers and to present dinosaurs

as realistically as possible. Before then, dinosaurswere brought to life for the screen by such

methods as sticking horns on lizards (Journey tothe Centre of the Earth, 1958), or manipulating

puppets off-screen (The Land That Time Forgot, 1974).

Realistic dinosaurmodel from theBBC film TheLost World,based on the novelby Sir ArthurConan Doyle,filmed in NewZealand in 2001

Computer animatronicsbring a herd ofstampeding dinosaursto life in the thirdJurassic Park film.

MANY PEOPLE ARE SO FASCINATED by dinosaurs that even thoughthese amazing creatures died out millions of years ago and nohuman has even seen one, there are plenty of places to find outmore about them. Museums of natural history or specialistdinosaur museums display life-sized reconstructions,often with sound effects or moving parts. You canalso take a virtual tour of many museums over the internet if you cannot visit them in person.Television programmes, such as the BBC’s Walkingwith Dinosaurs, or films such as Jurassic Park also give fascinating and realistic portrayals of the age of the dinosaurs.

ON A DINO DIGIt is possible to arrange to go on an actual dinosaur

dig or watch scientists at work in the field. Forexample, at the Dinosaur National Monument Quarry

in Utah, the United States (right), visitors can seeexcavation of fossils in progress. The Wyoming

Dinosaur Centre also offers dig tours where you canjoin palaeotechnicians on an active dinosaur dig. For

more information, log on to their website athttp://server1.wyodino.org/index.

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BEHIND THE SCENESOriginal fossil bones areextremely heavy so modernreconstructions usually uselightweight casts to make themounting easier. The originalbones are then housed in museumstorerooms and used for researchpurposes. Many museums havelaboratories, where scientistsstudy dinosaurs and other fossils.Some museums offer visitors the opportunity of watchingscientists at work.

VISIT A MUSEUMDinosaurs are often the most popular exhibits in natural history museums. Collections usuallyinclude full-size reconstructions to give people an impression of how dinosaurs might havelooked when they were alive. Some museums have computer-animated models that moverealistically, and sound effects. Look out, too, for travelling exhibitions from other museums,giving you the opportunity of seeing dinosaurs discovered in different parts of the world.

SEE “SUE”“Sue” is the name given to the largest and mostcomplete skeleton of a tyrannosaur everdiscovered. It was found by SueHendrickson in 1990, and bought bythe Chicago Field Museum. “Sue”went on display in 2000. Except forthe skull, the skeleton on display isthe real thing (not a plaster cast orplastic model). The bones were sowell-preserved, you can see finedetails where soft tissue, such asmuscles or tendons, were attached.

USEFUL WEBSITES

Places to visitNATURAL HISTORY MUSEUM Cromwell Road, Londonwww.nhm.ac.ukTouch-screens, interactive exhibits, and videos help you learn about prehistoric life. Highlights include:• robotic dinosaurs, especially the realisticanimatronic Tyrannosaurus rex• a huge 26-m (85-ft) long skeleton of Diplodocus

DINOSAUR ISLEYaverland, Isle of Wightwww.miwg.freeserve.index.htmFirst purpose-built dinosaur museum inEurope where several important finds havebeen made. It includes:• an animatronic Neovenator – a meat-eaterthat once roamed the Isle of Wight• the opportunity of going on fossil walks andwatching scientists at work

AMERICAN MUSEUM OF NATURAL HISTORYCentral Park West, New Yorkwww.amnh.orgFamous for its series of fossil halls, thismuseum currently has the largest number ofdinosaur skeletons on display. Highlightsinclude:• Tyrannosaurus, Apatosaurus, and Maniraptorskeletons• The only cast of a juvenile Stegoceras everfound, plus skin impressions of Edmontosaurusand Corythosaurus

FIELD MUSEUM OF NATURAL HISTORYLake Shore Drive, Chicagowww.fmnh.orgThe museum has exhibits covering 3.8 billionyears of life on Earth and includes:• “Sue”, the world’s largest and best-preserved Tyrannosaurus• Remains of some early dinosaurs discoveredin Madagascar, which may be older thanHerrerasaurus and Eoraptor

SMITHSONIAN MUSEUM OF NATURALHISTORYWashington, DCwww.mnh.si.eduThis is one of the largest collections in theUnited States and highlights include:• dioramas recreating scenes from the Jurassicand Cretaceous periods• a discovery room where you are allowed tohandle fossils and arrange to watch scientistsworking in the Fossil Laboratory

DINOSAUR NATIONAL MONUMENT QUARRYUtah, USAwww.nps.gov/dino/dinos.htmSite where some of the largest finds from the Jurassic Period have been discovered,highlights include:• the opportunity of watching scientists atwork in the field• displays of some of the North Americandinosaurs made here, including long-neck,plant-eating sauropods• a sandstone cliff in which over 1,600 boneshave been exposed, which makes up one wallof the Visitor’s Centre

Sue’s mouth wasfilled with long,pointed teeth; shemay also havesuffered fromtoothache – fiveholes in her lowerjaw are thought to be places of infection

Diplodocusskeleton, ondisplay in theentrance hall of the NaturalHistory Museum,London

New thinking suggests that Diplodocus would not have been able to raise its long neck higher than its shoulders

• Plenty of facts for serious dinosaur enthusiasts:www.dinodata.net

• National Geographic site, including animation:www.nationalgeographic.com/dinorama

• General, award-winning site, with a discussion group:www.dinosauria.com

• Video clips of dinosaurs from Walking with Dinosaurs:www.bbc.co.uk/dinosaur

• For a virtual tour of the dinosaur galleries at the Smithsonian National Museum of Natural History:www.nmnh.si.edu/paleo/dino/

• Dinosaur and fossil links:www.sciencespot.net/Pages/kdzdino.html

ALLOSAUR (“strange lizard”) Primitivetetanuran theropod (large meat-eatingdinosaur).

AMMONITE One of an extinct group ofcephalopods with a coiled, chambered shell that lived in Mesozoic seas.

AMPHIBIAN Cold-blooded vertebrateoriginating in the Carboniferous Period,whose young use gills to breathe during the early stages of life. Living amphibiansinclude frogs, newts, and salamanders.

ANKYLOSAUR (“fused lizard”) Four-legged, armoured, plant-eating,ornithischian dinosaur with bony platescovering the neck, shoulders and back, and a horny beak used for cropping plants.

AVES Birds, which probably evolved fromtheropod dinosaurs in the Late JurassicPeriod. Some scientists only use “Aves” for modern birds, calling the most primitivebirds “Avialae”.

BIPEDAL Walking on two hindlimbs, rather than on all fours.

BRACHIOPOD Marine invertebrate with a two-valved shell, which evolved in theCambrian Period.

CARNIVORE Meat-eating mammal withsharp teeth, such as a cat, dog, bear, or oneof their relatives and ancestors; sometimesused to describe all meat-eating animals.

CARNOSAUR Large meat-eating dinosaur with a

big skull and teeth.The name was onceused for all suchtheropods but isnow restricted toAllosaurus and

its relatives.

CEPHALOPOD Marine mollusc with largeeyes and well-developed head ringed bytentacles, such as an octopus, squid orcuttlefish.

CERATOPIAN or CERATOPSIAN(“horned face”) Bipedal and quadrupedalplant-eating ornithischian dinosaur, with a deep beak and a bony frill at the back of its skull.

CERATOSAUR (“horned lizard”) One oftwo major groups of theropods.

COLD-BLOODED Depending upon theheat from the sun for body warmth. (see alsoWARM-BLOODED)

CONIFER Tree that bears cones, such as apine or fir.

COPROLITEFossilized

dung.

CRETACEOUS PERIOD Third period of the Mesozoic Era, 145-65 million years ago.

CYCAD Palm-like, seed-bearing plant with long fern-like leaves.

DIPLODOCID (“double beam”) Plant-eating sauropod; one of a family of hugesaurischian dinosaurs with long necks andlong tails.

DROMAEOSAURID (“running lizard”)Bird-like, bipedal, carnivorous dinosaur.

DUCKBILLED DINOSAUR (seeHADROSAUR)

EMBRYO Plant or an unborn animal in anearly stage of development.

EVOLUTION The process bywhich one species gives rise

to another. Evolutionoccurs when

individualorganisms

pass onmutations (chance

changes in genes controlling body size,shape, colour, and so on). Individuals withbeneficial mutations pass them on. Theirkind multiplies, and new species arise.

EXTINCTION The dying-out of a plant or animal species.

FOSSIL The remains of something that oncelived, preserved in rock. Teeth and bones aremore likely to form fossils than softer bodyparts, such as internal organs.

GASTROLITH Stones swallowed by someanimals, such as sauropods, to help grind up food in the stomach.

GENUS (plural, GENERA) Group of relatedorganisms, ranked between the levels offamily and species.

GINGKO Deciduous tree that grows toaround 25 m (115 ft) in height, which

evolved in the Triassic Period andsurvives essentially unchanged

to this day.

HADROSAUR (“bulkylizard”) Duck-billeddinosaur; large,bipedal/quadrupedal

ornithopod from the Late Cretaceous Period

with a duck-like beak used for browsing on vegetation.

HERBIVORE Animal that feeds on plants.

IGUANODONTIAN (“Iguana teeth”) Large, bipedal/quadrupedal plant-eatingornithopod from the Early CretaceousPeriod. (see also ORNITHOPOD)

INVERTEBRATE Animal without a backbone.

JURASSIC Second period of the MesozoicEra, 200–145 million years ago.

MAMMAL Warm-blooded, hairy vertebratethat suckles its young.

MANIRAPTORAN (“grasping hands”)Tetanuran theropod with long arms andhands, including predatory dinosaurs such as Velociraptor, and birds.

MEGALOSAUR (“great lizard”) Primitivetetanuran theropod, less advanced than an allosaur.

MESOZOIC “Middle life” geological eraabout 250–65 million years ago, containingthe Triassic, Jurassic and Cretaceous periods;and the “Age of the Dinosaurs”. Dinosaursbecame extinct at the end of the era.

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Glossary

Fossil of a plesiosaur flipper

Hadrosaur (Corythosaurus)

Ginko

ORNITHISCHIAN (“bird hips”) One of two main dinosaur groups. In ornithischiandinosaurs, the pelvis is similar to that of birds. (see also SAURISCHIAN)

ORNITHOPOD (“bird feet”) Bipedalornithischian dinosaur with long hindlimbs.

OVIRAPTORID (“egg stealer”)Maniraptoran theropod dinosaur with a beak and long legs.

PACHYCEPHALOSAUR (“thick-headedlizard”) Bipedal ornithischian dinosaur with a thick skull.

PALAEONTOLOGIST Someone whostudies palaeontology.

PALAEONTOLOGY The scientific study of fossilized plants and animals.

PALAEOZOIC “Ancient life” geological erafrom 540–240 million years ago, containingthe Cambrian, Ordovician, Silurian,Devonian, Carboniferous, and Permianperiods.

PLESIOSAUR Large Mesozoic marinereptile with flipper-shaped limbs and (often)a long neck.

PREDATOR Animal or plant that preys on animals for food.

PRESERVATION Keeping something (suchas a fossil) free from harm or decay.

PROSAUROPOD Early plant-eatingsaurischian dinosaur that lived from the Late Triassic to Early Jurassic eras.

PSITTACOSAUR (“parrot lizard”)Ceratopian ornithischian plant-eater fromthe Cretaceous Period. A psittacosaur wasbipedal with a deep, parrot-like beak.

PTEROSAUR (“winged lizard”) Flyingreptile of the Mesozoic Era, related to the dinosaurs.

QUADRUPEDAL Walking on all fours.

REPTILE Cold-blooded, scaly vertebratethat reproduces by laying eggs or givingbirth on land. Living reptiles includelizards, snakes, turtles, and crocodiles.

SAURISCHIAN (“lizard hips”)One of two main dinosaurgroups. In saurischian dinosaurs, the pelvis is similar to that of lizards (see alsoORNITHISCHIAN)

SAUROPOD (“lizard feet”)Huge, plant-eating quadrupedalsaurischian dinosaur thatlived through most of theMesozoic Era.

SAUROPODOMORPH (“lizard foot form”) Large plant-eatingquadrupedal saurischian dinosaur,including the prosauropods and sauropods.

SCUTE Bony plate with a hornycovering set into an animal’s skin to protect it from an enemy’s teethand claws.

SEDIMENT Material deposited bywind, water, or ice.

SKULL The head’s bony frameworkprotecting the brain, eyes, ears, andnasal passages.

SPECIES The level below genus in the classification of living things.

Individuals in a species can breed to produce

fertile young.

STEGOSAUR(“plated/roofedlizard”) Plant-eating, quadrupedalornithischian dinosaur withtwo tall rows of bony platesrunning down its neck, back, and tail.

TETANURAN (“stiff tail”) One of the two main groups of theropod dinosaurs.

THECODONT (“socket teeth”) One of amixed group of archosaurs, which includesdinosaurs, crocodiles, and pterosaurs.

THEROPOD (“beast feet”) One of a group of predatory dinosaurs with sharp teeth and claws.

TITANOSAUR (“gigantic lizard”) Huge,quadrupedal plant-eating sauropod.

TRACE FOSSIL Trace left by a prehistoriccreature, such as its footprints, eggs, bitemarks, droppings, and fossil impressions of skin, hair, and feathers.

TRIASSIC First period of the Mesozoic Era,about 250–200 million years ago.

TYRANNOSAURID (“tyrant lizard”) Huge,bipedal carnivorous tetanuran theropodcharacterized by a large head, short arms,two-fingered hands, and massive hindlimbs;flourished during the Late Cretaceous Periodin North America and Asia.

WARM-BLOODED Keeping bodytemperature at a constant level, often above or below that of the surroundingenvironment, by turning energy from foodinto heat. (see also COLD-BLOODED)

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Tyrannosaurid(Tyrannosaurus)

Cycad

Dromaeosaurid (Velociraptor)

Dorling Kindersley would like to thank: Angela Milner and the staff of the BritishMuseum (Natural History); Kew Gardensand Clifton Nurseries for advice andplant specimens for photography; TrevorSmith’s Animal World; The Institute ofVertebrate Palaeoanthropology, Beijing,for permission to photograph Chinesedinosaurs; Brian Carter for obtainingplant specimens; Victoria Sorzano fortyping; William Lindsay for advice onpp52-53 and pp 54-55; Fred Ford andMike Pilley of Radius Graphics; JaneParker for the index; Richard Czapnik for design assistance; and Dave King for special photography on pp6-7 andpp10-11.

Picture creditst=top, b=bottom, m=middle, l=left, r=right

American Museum of Natural History: 44bl, 54tl;/C. Chesak 42bl;

ANT/NHPA: 7tr;Artia Foreign Trade Corporation: /ZdenekBurian 10m;

BBC Hulton Picture Library: 8tl, 9tm, 31t;Booth Museum of Natural History: 50b;The Bridgeman Art Library: 17bl;The British Museum (Natural History): 52tl,52ml, 55tr;

Bruce Coleman Ltd: 14-15; /Jane Burton 6ml,13br, 29ml, 35tl, 36tl, 39tr, 50tl, 57bl, 59tl; /JulesCowan 51br; /Janos Jurka 34tl;

Corbis: 69b; /James L. Amos 68mr; /Tom Bean64-65; /Derek Hall/Frank Lane Picture Agency68tl;

Albert Dickson: 46bl;Alistair Duncan: 71ml;Robert Harding: 63tr;The Illustrated London News: 46tl;The Image Bank: /L. Castaneda 15mr;

Illustrations by:Bedrock: 12m, 14tl;Angelika Elsebach: 21tl, 36b;Sandie Hill: 20br, 28tr, 44tr;Mark Iley: 18bl;Malcolm McGregor: 43bl;Richard Ward: 26bm, 47b;Ann Winterbotham: 10tl;John Woodcock: 6tr, 7mr, 14b, 14ml

Acknowledgments

Index

AAlbertosaurus 60allosaur 67, 70Allosaurus 23, 38, 64, 67,70

ammonite 48, 60, 70amphibian 56, 70ankylosaur 20, 21, 22, 27,32, 33, 64, 66, 70

Apatosaurus 12, 43, 62, 69Archaeopteryx 50, 51Argentinosaurus 12, 65armadillo 32, 33armour 22, 32, 33, 59armoured dinosaur seeankylosaur

Aves see bird

BBambiraptor 50, 51Barosaurus 38, 54Baryonyx 43, 53, 55, 64beetle 56bird 22, 29, 44, 48, 50, 51,58, 59, 66, 70

birth of dinosaurs 46brachiopod 61, 70Brachiosaurus 12, 14-15brain 35, 14, 64Brontosaurus 62

CCamarasaurus 19, 62camouflage 21, 32, 65Captorhinus 56Carcharodontosaurus 65carnivore 23, 33, 36, 38, 70see also meat eater

carnosaur 24-25, 34, 64, 70Caudipteryx 50, 51ceratopian 14, 19, 26, 30-31, 44, 46, 65, 66, 70

ceratosaur 67, 70Ceratosaurus 25chevron bone 18, 19, 34,35

claw 42-43, 64cockroach 59coelacanth 56Coelophysis 50, 51, 67

GGallimimus 36, 67Gastonia 20gastrolith 26, 70gastropod 59Giganotosaurus 64, 65ginkgo 11, 50, 70Gorgosaurus 25grey plover 58growth 46, 47Gryodus 58

Hhadrosaur 10, 21, 26, 27,28, 45, 46, 49, 66, 70

hand 38-39Hawkins, Benjamin 9, 55head 28-29herbivore 10, 21, 23, 36,38, 70 see also plant eater

Herrerasaurus 65, 67, 69Heterodontosaurus 36hip bone 6, 18, 49, 71holly 11horned dinosaur seeceratopian

horse 61horsetail 10, 11, 27human 22, 27, 61Hylaeosaurus 8Hypacrosaurus 64Hypsilophodon 36, 37, 62,63, 66

Hyracotherium 61

Iichthyosaur 48, 57, 60, 62iguana 6, 7, 8, 26Iguanodon 6, 8, 9, 25, 27,39, 40, 49, 54, 59, 64, 66

iguanodontian 66, 70insect 13, 24, 61

JJurassic Park 68Jurassic Period 56, 58, 59,70

Kkangaroo 18king crab 58

Llaurel 11leg 6, 16, 36-39Lesothosaurus 66lion 25lizard 6, 13, 20, 31, 32, 58,59, 60, 61

lobster 60Lost World, The 68lungfish 56

Mmagnolia 11Maiasaura 44, 46, 64Mamenchisaurus 65mammal 24, 60, 70Maniraptor 69Mantell, Dr Gideon 8, 9Mantell, Mary Ann 8marsupial 60Massetognathus 57Massospondylus 23, 42meat eater 14, 19, 20, 22,23, 24-25, 30, 32, 42, 43,50 see also carnivore

megalosaur 67, 70Megalosaurus 8, 25, 64Megazostrodon 57Micropachycephalosaurus65

Minmi 65monkey puzzle tree 11Morosaurus 19mosasaur 48, 60Mosasaurus 52muscle 14, 15, 18, 19, 54

Nneck 14, 15Neovenator 69nest 44-45, 46Nuthetes 25

Oomnivore 23, 42, 57ornithischian dinosaur 6,66-67, 71

ornithomimid 64Ornithomimus 42ornithopod 66, 71Ornithosuchus 7ostrich 36, 37Oviraptor 44-45, 64

Scutellosaurus 66sedimentary rock 52Seismosaurus 23, 65shark 61Sinornithosaurus 50skin 32, 54, 65, 69sloth 8Smith, William 9snake 59Staurikosaurus 7Stegoceras 69stegosaur 20, 21, 34-35, 66, 70

Stegosaurus 21, 34, 35, 65Struthiomimus 36Styracosaurus 31“Sue” 69

Ttail 18-21teeth 6, 8, 10, 22, 23, 24-25, 26, 27, 29, 36, 59

tetanuran 67, 71thecodont 7, 57, 71Thecodontosaurus 57Therizinosaurus 43theropod 24, 65, 67, 68, 70, 71

titanosaur 64, 65, 67, 71toe bone 38, 40Torosaurus 65trace fossil 40, 71Triassic Period 56, 71Triceratops 6, 14, 26, 30-31,38, 65, 66

trilobite 56Troodon 24, 50, 64tuatara 7Tuojiangosaurus 34-35turtle 60, 61Tyrannosaurus 6, 14, 24, 30, 39, 49, 64, 69, 71

VVelociraptor 42, 64, 70, 71

Wwarm-blooded 65, 70wishbone 50, 51

Yyew 26

oviraptorid 67, 71Owen, Sir Richard 8

Ppachycephalosaur 66, 71Pachycephalosaurus 28, 29palaeontologist 52, 53, 71Paralitan 12Parasaurolophus 10, 28, 29,65

pareiasaur 54passion flower 11Piatnitzkysaurus 64pine tree 26, 27Pisanosaurus 66plant 10, 11, 23, 26, 29, 60, 61

plant eater 12, 20, 22, 23,26, 30, 34, 39, 42 see alsoherbivore

plated dinosaur seestegosaur

Plateosaurus 39, 67plesiosaur 48, 58, 62, 70,71

Polacanthus 32Procolophon 56prosauropod 67, 71Proterosuchus 7Protoceratops 45, 46, 47, 64psittacosaur 66, 71Psittacosaurus 29, 65Pterodactylus 58pterosaur 6, 22, 48, 58, 59,70

Qquail 44

Rrhinoceros 30Riojasuchus 57rodent 61

SSaltasaurus 64saurischian dinosaur 6,66-67, 71

sauropod 12, 13, 18, 19,20, 21, 23, 26, 27, 33, 38,46, 64, 67, 69, 70, 71

Scelidosaurus 20, 38, 66scorpion 56

coelurosaur 24cold-blooded 65, 70Compsognathus 12, 13, 37,67

computer modelling 54,68, 69

conifer 10, 14, 15, 23, 26,70

coprolite 64, 70Corythosaurus 28, 69, 70crab 60Cretaceous Period 56, 59,60, 61, 70

crocodile 7, 20, 32, 48, 57,58, 59, 71

cycad 10, 11, 15, 26, 27, 57,70, 71

Ddeadly nightshade 48defence 14, 20, 21, 25, 28,30, 33, 35, 38, 42

Deinonychus 19, 42, 65digestion 26, 70Diictodon 56Dimetrodon 35diplodocid 67, 70Diplodocus 14-21, 23, 33,38, 43, 46, 62, 69

discovery of dinosaurs 8dogwood 11dragonfly 58dromaeosaurid 64, 67, 70,71

Dryosaurus 59duckbilled dinosaur seehadrosaur

EEchinodon 26Edmontonia 33, 66Edmontosaurus 27, 28, 69egg 44-45, 46, 48, 64, 65,71

Eoraptor 64, 69Euoplocephalus 20, 21Euparkeria 7extinction 6, 48-49, 60

Ffeeding 14, 15, 22, 64fern 10, 11, 15, 27fish 58, 60flowering plant 10, 11footprint 40, 64, 71forest 10, 11, 14

Kobal Collection: 63m; Jurassic Park III © ILM(Industrial Light & Magic) 68bl;

The Mansell Collection: 28tl, 42mr, 56tr;Mary Evans Picture Library: 9bl, 9m, 12tl, 16bl,25ml, 34ml, 35bm, 62tl, 62bl, 62mr;

Museo Arentino De Cirendas Naterales, BuenosAires: 64bl;

The Natural History Museum, London: 23bl,64tl, 65tm, 68-69;

Natural Science Photos: /Arthur Hayward 24tr,29bl, 37tr; /G. Kinns 30tl; /C.A. Walker 40tl;

David Norman: 53mr;Planet Earth Pictures: /Richard Beales 32tl; /KenLucas 31mr;

Rex Features: 66-67, 69m; /Simon Runtin 68br;Royal Tyrrel Museum, Canada: 66mr, 70-71;Science Photo Library: /David A. Hardy 49tl;/Philippe Plailly/Eurelios 65ml, 69t;

The South Florida Museum of Natural History:51tr, 51cr

Picture research: Angela Murphy, Celia Dearing

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