1. Figure 3.1 Paleozoic amphibians, Crassigyrinus (group, incertae sedis) and Diplocaulus (Nectridea). Adapted from Milner et al., 1986, and Milner, 1980.

2. Figure 3.2 Geological occurrence of some early tetrapods, and extinct and living amphibians. Abbreviations for Cenozoic epochs: Paleo, Paleocene; Eo, Eocene; Oligo, Oligocene; Mio, Miocene; Pli, Pliocene; Pleistocene is the narrow, unlabeled epoch on the far right side of the chart. The Dicamptodontidae is now included in Ambystomatidae.

3. Figure 3.3 Seymouria, an Early Permian anthracosaur from Texas. Scale: bar = 5 cm. (R. S. Clarke)

4. Figure 3.4 Triassic landscape showing early reptiles including the dycinodont Placerias (left), a group of theropods in the genus Coelophysis (right), several phytosaurs (crocodile-like), and a group of metaposaurs (labyrinthodont amphibians). By Karen Carr, with permission of the Sam Noble Oklahoma Museum of Natural History.

5. Figure 3.5 Triadobatrachus massinoti, the earliest known frog, from the Triassic of Madagascar. Adapted as a partial reconstruction from Estes and Reig, 1973. Scale bar = 1 cm.

6. Figure 3.6 Albanerpetontidae, salamander-like lissamphibians from the Cretaceous and Tertiary. Skull of Albanerpeton and morphology of Celtedens ibericus. After Estes and Hofstetter, 1976, and as suggested by skeleton in McGowan and Evans, 1995, respectively.

7. Figure 3.7 Karuarus sharovi (about 15 cm TL), the earliest known salamander, from the Late Jurassic of Russia. Adapted as a partial reconstruction from Carroll, 1988.

8. Figure 3.8 Vieraella herbstii, an ancient frog from the Jurassic of Patagonia. Scale bar = 2 mm. Adapted from Estes and Reig, 1973.

9. Figure 3.9 Paleobatrachus grandiceps, a representative of the extinct Paleobatrachidae, from the Oligocene of eastern Europe. Scale bar = 10 mm.Adapted from Estes and Reig, 1973.

10. Figure 3.10 Geological occurrence of some early anthracosaurs and amniotes, and extinct and living reptiles. Abbreviations for Cenozoic epochs: Paleo, Paleocene; Eo, Eocene; Oligo, Oligocene; Mio, Miocene; Pli, Pliocene; Pleistocene is the narrow, unlabeled epoch at the top of the chart. Asterisk indicates insuffficient fossil material to depict how long the taxon persisted.

11. Figure 3.11 Hylonomus lyelli, the earliest known reptile, from the Early Permian of Nova Scotia. Size, about 42 cm SVL. Adapted from Carroll and Baird, 1972.

12. Figure 3.12 Pareiasaurus karpinksyi, a pareiasaur from the Late Permian of Russia (about 3 m TL). Adapted from Gregory, 1951.

13. Figure 3.13 The Ichthyosaur Ichthyosaurus intermedius was one of the large marine reptiles present during the Jurassic. Photograph by Sarah Riebolt, courtesy of the Museum of Paleontology, University of California, Berkeley.

14. Figure 3.14 Cretaceous sea showing several typical reptiles, including the turtle Protostega (left), the mosasaur Platecarpus (largest reptile), and a plesiosaur (top). The extinct bony fish Xiphactinus (bottom right) and the aquatic bird Hesperornis (center right) are also shown. By Karen Carr, with permission of the Sam Noble Oklahoma Museum of Natural History.

15. Figure 3.15 Top: The sauropsid reptile Mecistotrachelos apeoros was one of several gliding reptiles in the Triassic. Its large limbs suggest that it may have been arboreal. It had a much longer neck than that of other gliding reptiles such as Kuehneosaurus and Icarosaurus (by Karen Carr, with permission of the Virginia Museum of Natural History). Middle: Skeleton of Kuehneosaurus, a diapsid glider, from the late Upper Triassic showing ribs modified to support the airfoil. Scale: bar = 4 cm (adapted from Robinson, in Romer, 1966). Bottom: Draco jareckii, an Agamid lizard that glides using a rib-supported airfoil (R. M. Brown).

16. Figure 3.16 Cretaceous coastal scene showing several reptiles characteristic of the period, including the carnivorous Dienonychus (left; some restorations show Dienonychus with feathers), the coelurosaurian Ornithodesmus (in the air), and a group of the ornithopod dinosaurs Tenontosaurus. By Karen Carr, with permission of the Sam Noble Oklahoma Museum of Natural History.

17. Figure 3.17 Jurassic scene showing typical reptiles including a Stegosaurus (lower left), an Apatosaurus (largest), the carnivorous Saurophaganax (bipedal), a group of Camptosaurus (right), and two Archeopteryx (flying). By Karen Carr, with permission of the Sam Noble Oklahoma Museum of Natural History.

18. Figure 3.18 Cranial structure of ancient crocodilians: the aetosaur Stegonolepis (above) of the Upper Triassic and an unnamed Edentosuchus-like protosuchid of the Early Jurassic. Scale bar = 1 cm. Adapted from Walker, 1961 and Seus et al., 1994, respectively.

19. Figure 3.19 Cranial structure of the marine sphenodontidan Pleurosaurus from the Late Jurassic. Scale bar = 1 cm. Adapted from Carroll and Wild, 1994.

20. Figure 3.20 Proganochelys quenstedti, the most ancient turtle, from the Lower Triassic of Germany; approximately 15 cm CL. From Gaffney, 1990; courtesy of the American Museum of Natural History.

21. Figure 3.21 Skulls of two extinct taxa of North American lizards, the Middle Oligocene wormlizard Rhineura hatcheri (top; lateral view) and the Middle Oligocene glyptosaurine Peltosaurus granulosus (bottom; dorsal view). Adapted from Gilmore, 1928.

22. Figure 3.22 The structure of the head of the fossil snake Pachyrhachis problematicus (upper) was reconstructed using X-ray computed tomography (lower image), showing that the skull is indeed that of a basal macrostomatan snake, which means that limb loss occurred independently in different snake clades. Adapted from Polcyn et al., 2006.

23. Figure 3.23 The newly described fossil snake Najash not only has bony elements of the sacrum and hindlimbs but was also terrestrial/subterranean. Combined with other skeletal features, Najash appears to be sister to all known snakes, suggesting that snakes had a terrestrial origin rather than a marine one. Elements of the pelvis and hindlimbs are shown for Najash, Pachyrhachis, and the Boinae for comparison. Adapted from Apesteguía and Zaher, 2006

24. Figure 3.24 Trunk vertebrae from the Upper Cretaceous snake, Dinilysia patagonica; dorsal view of a series of four vertebrae (top), anterior view (bottom left) and lateral view (bottom right) of individual vertebrae. Adapted from Rage and Albino, 1989.