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

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/subterranea
n. 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.