iii) Reptiles-Dinosaurs

By: Camila Rodriguez

Dinosaurs Not the first reptile Triassic period Cretaceous period Diapsid skull

Reason for the name

From the Latin word 'reptilis' Means 'creeping’

# of species currently existing 9,475 species Divided in 4 groups: Crocodilia, Squamata, Testudines and

Sphenodontia. Crocodilia: alligators, crocodiles, caimans and gharials. Squamata: Snakes and Lizards Testudines: tortoises and turtles Sphenodontia: tuataras

Crocodilia Squamata

Testudines Sphenodontia

Reptile characteristics Vertebrates=have backbone/internal skeleton Cold blooded Lay eggs on land (amniote eggs) Get oxygen from lungs Dry scaly skin Hatch into young adults 3 chambered heart (alligators and crocodiles) 2 aortic blood vessels 4 or no legs Internal fertilization

“Fossil record”

Oldest fossil 315 million years - Hylonomus (late Carboniferous period)

Life Cycle Some lay their eggs and some give live birth.

(oviparous) Some reptiles stay with their parents when born Grows becoming an adult Female fertilize internally producing the eggs They can reproduce more than once After giving birth they die Asexual reproduction

Life Expactancy Giant Tortoise: 152 years Box Turtle 123 years Alligator 68 years Snapping Turtle 57 years Cobra 28 years Cottonmouth 21 years

Digestive System Very simple Mouth Salivary gland- softens and moistens food Esophagus- a tube in which the food goes from the pharynx to the

stomach Intestine- from stomach to anus Cloaca- outlet into the intestinal, urinary, and genital open Eat Most reptiles are carnivores feed on small invertebrates (mammals,

reptile) Some are herbivores feed on plant such as grasses, fruits, shrubs and

marine plants.

Respiratory System Breath using lungs Gas exchange in reptiles occurs in the alveoli

( diaphragm) Breathing occurs in a change in the volume of

the body cavity. Controlled by contraction of intercostal muscles.

Turtles and tortoise Ventilation of the lungs sheets of muscle in the shell that, through

contraction and relaxation, force air in and out of the lungs

Circulatory System Closed system 3 chambered hearts with two atria Blood flows through heart Mixing of oxygenated and deoxygenated

blood

Sensory System They feel pain, temperature, pressure, and stretching at the dermal level. Crocodilia

Vertical cat-like pupil excellent diurnal / nocturnal vision External ears Eardrums Nostril

Squamata Eyelids- spectacle Smell with their tongue Ears

Testudines smell Ears: only hear vibrations and changes in water pressure Night vision

Sphenodontia Great vision Third eye Weak taste buds

Sensory System

Bibliography http://staff.tuhsd.k12.az.us/gfoster/standard/breptil.htm http://animals.about.com/od/zoologybasics/a/

howmanyspecies.htm http://cowgirljess.hubpages.com/hub/The-Four-Groups-of-

Reptiles http://honorsbiologyp6.wikispaces.com/Reptiles+-+Sensory+

Systems http://www.exoticpetvet.net/reptile/rerepro.html http://www.britannica.com/EBchecked/topic/498684/reptile/3

8474/Digestive-and-urogenital-systems

http://www.sandiegozoo.org/animalbytes/t-lizard.html