tetrapoda lab 8 (chapters 18, 19, and 20) exam next...
TRANSCRIPT
Tetrapoda Lab 8 (Chapters 18, 19, and 20) Exam Next Week!
•! I will grade today’s lab for you before
you go, so you can take it with you to
study.
Taxonomy of phylum Chordata •! Subphylum Urochordata – sea squirts
•! Subphylum Cephalochordata - amphioxus
•! Subphylum Vertebrata –! Superclass Pisces
•! Class Agnatha
•! Class Chondrichthyes
•! Class Osteichthyes
–!Superclass Tetrapoda •!Class Amphibia
•!Class Reptilia
•!Class Aves
•!Class Mammalia
(a) Chick embryo
Gill pouches
Post-anal tail
(b) Human embryo
Phylum Chordata –!4 defining characteristics
•! Notochord
•! Dorsal, hollow nerve cord
•! Pharyngeal gill slits
•! Post-anal tail
Jaw
Bones
Legs
Amniotic egg
Milk / Fur Feathers
Amphibia: salamanders and
newts, frogs and toads, and
caecilians
Class: Amphibia
•! Ectothermic - can’t heat itself
•! Still tied to water
•! 3-chambered heart
•! Tetrapod legs to side of body
Amphibia
Colostethus
Frog external anatomy (no scales; naked)
•! Cross-section slide (skin):
epidermis, dermis, mucous glands,
poison glands
Class: Amphibia
www.wickersham.us/anne/frog.htm
Tympanic
membrane
•! Know the difference between a frog and a toad (parotoid gland)
Class: Amphibia
American toad
Bull Frog
•!Frog larva
Tadpole
Class: Amphibia Class: Reptilia Turtles,
Tortoises, Lizards, Snakes,
Crocodiles, Alligators, Tuatara
Class: Reptilia
•! Ectothermic (except shivering pythons)
•! No longer tied to water (amniotic egg)
•! 3-chambered heart
(4 in Croc and some monitor lizards)
•! Tetrapod legs to side of body
Class:
Reptilia
Class: Reptilia (amniotic egg) Reptile scales Epidermal in origin
Fish skin
Reptile scales •! For keying, look in the center of the
back
Reptile scales
Bony Dermal Plates
•! Turtle - Know the carapace (dorsal) and plastron (ventral)
Scale type: Bony Dermal Plates
Class: Reptilia •! Turtle - Know the carapace (dorsal) and plastron (ventral)
Scale type: Bony Dermal Plates
Class: Reptilia
male's plastron
is concave
female's plastron
is flat
Keying:
•! Use the dichotomous keys to determine
the taxonomy of the amphibian and
reptile specimens in lab.
Class: Amphibia & Reptilia Characteristics for Keys
Cloacal opening
Longitudinal Slit Transverse Slit
Characteristics for Keys
Pupil of eye
Pupil Vertical Pupil not Vertical
Characteristics for Keys PIT between eye and nostril
Characteristics for Keys
Parasphenoid (or vomerine) teeth
Roof of mouth
Characteristics for Keys
Tongue bicornuate behind
Tongue attached in the front
Class: Aves (birds) Class: Aves •! Endothermic
•! Feathers (modified scales)
•! Flight (some exceptions)
•! Hollow bones (why?)
•! Crop and Gizzard (no teeth)
•! 4-chambered heart
•! Amniotic egg
Class: Aves (birds) Bird feathers
Types: Down, filoplume, contour
warmth
Decoration
Flight
Class: Aves (birds) Bird feathers
Contour (flight) Feather
Construction:
Quill (Calamus), Shaft (Rachis)
Class: Aves (birds) Bird feathers
Contour (flight) Feather
Construction:
Barbs, Barbules
Class: Aves (birds) Bird beaks and feet:
Mandible
(lower bill)
Maxilla
(upper bill)
Class: Mammalia
•! Endothermic
•! Hair (insulates the body)
•! Mammary glands, (produce milk; nourish young)
•! 4-chambered heart
There are three major groups of
mammals
1.! Monotremes - the egg-laying mammals.
Platypus with pups echidna
2.! Marsupials - the so-called pouched
mammals (short gestation period)
Example: kangaroos, wallabies
3.! Placentals - most mammals
–!Have a relatively long
gestation period
–!Complete embryonic
development occurs
within the mother
Figure 18.22C