1. Comparative Anatomy Vertebrate Phylogeny: Amphibians, Reptiles, and Birds
Kardong Chapter 3
Part 5

2. Amphibian Characteristics
1st vertebrates to possess cervical vertebrae
Lost scales
Some primitive frogs have dermal scales
Anamniotic eggs
3 chambered heart
Metamorphosis
10 pairs of cranial nerves
2 occipital condyles

3. Modern Amphibians Order Caudata Order Anura Order Gymnophiona (Apoda)
Figure 5.1.

4. Reptiles (the Parareptilia and Eureptilia)
Mesozoic Era - Age of Reptiles
Carboniferous - Divided into Pennsylvanian (upper)
and Mississippian (lower)
Extinction took place at end of Paleozoic Era with placoderms
Figure Carboniferous Period.

5. Labyrinthodont amphibians led to stem reptiles- cotylosaurs (p. 109)
Figure Cotylosuars, stem reptiles.
Labyrinthodont amphibians led to stem reptiles- cotylosaurs (p. 109)
Which gave rise to all reptiles and mammals

6. Figure Phylogenetic
grouping of amniotes (book
figure 3.30.).

7. Phylogeny of Amniote Groups
Figure 5.5.

8. Reptilian Characteristics
True claws
Amniotic eggs
No metamorphosis
12 pairs of cranial nerves
Single occipital condyle
Figure Nile monitor.
Figure Reptile egg.

9. Reptilian Classification
Parareptilia - anapsida (today applies to skull type)
Order Testudines (Chelodina)
Ex: turtles
Diapsida (within the Eureptilia)
Majority of reptiles
Order Squamata
Ex: lizards and snakes
Suborders Serpentes and Sauria
Order Sphenodontida
Ex: tuatara (Sphenodon)
Order Crocodylia

10. Reptilian Oral Cavity Tooth type Acrodont Pleurodont Thecodont
Tooth on surface of jaw
Ex: fish and Sphenodon (tuatara)
Pleurodont
Tooth attached on medial surface of jaw
Ex: lizards and snakes
Thecodont
Teeth embedded in jaw bone
Ex: crocodile
Figure Jaw cross section.

11. Skull Type Amniotes possess different skull types
Figure Skull types.
Amniotes possess different skull types
Anapsid- lack temporal fossa
Diapsid- two temporal fossa
One dorsal and one ventral
Synapsid- single, lower temporal fossa
Gave rise to mammal-like reptiles
Figure Sarcopterygian skull.

12. Reptilian Radiation Figure 5.11. Phylogenetic tree of reptiles.
Figure Relationships among
higher vertebrates.

13. “Sea Serpents” Pliosaur (a type of plesiosaur).
Mayborn Museum, Baylor University
“Sea Serpents”
Nothosaurus (Berlin Natural History Museum)

14. Dinosaur Groups Morphological character of pelvis separate groups
Saurischians
Triradiate pelvis
Lizard-like
Ornithischians
Tetraradiate pelvis
Bird-like
Figure Pelvic of two dinosaur groups (book figure 3.35).

15. Figure 5.14. Size of selected dinosaurs.

16. Dinosaur Groups (cont.)
Saurischians
Gave rise to dominant
reptiles
Birds evolved
Parallel convergence
Figure Reptilian cladogram.

17. Aves - Birds Archeopteryx- discovered in 1861 – ancestral bird
Feathers and teeth present
Read “Discovery of the First Bird” – p. 119.
Figure Archeopteryx fossil.

18. Birds (cont.) Keeled sternum in birds that fly. (carinates)
Flightless birds (ratites)
Figure (a) Archaeopteryx (b) pigeon.

19. Relative Diversity of Terrestrial Vertebrates
Fig

20. Characteristics of Birds
Feathers present
Homeothermic
Single occipital condyle
Scales on legs and feet
Figure 5.19.

21. Flier and Flightless Birds
Archeopteryx- glider
Reduced sternum
Figure (a) Archaeopteryx (b) pigeon.

22. Avian Classification Modern birds - Subclass Neornithes
Ancient birds - Subclass Archaeornithes
Passeriformes - largest order of birds
Birds arose in mid-Jurassic Period