“Reptile” Diversity and Evolution
George A. Lozano
Department of Biology
University of Ottawa
George A. Lozano2
Summary
� Sauropsids
� Turtles
� Diapsids/Saurians
� Plesiosaurs† and ichthyosaurs †
� Lepidosaurs� Tuatara
� Squamates (snakes, geckos, iguanas, monitors)
� Archosaurs (crocodiles, dinosaurs, pterosaurs)
� Dinosaurs
Amniota
Synapsida Sauropsida
Diapsida Turtles
Ancestral amniotes & Turtles
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Turtles - Testudina
� 250 species
� Carapace (vertebrae and ribs)
� Appendicular girdles INSIDE the shell
� Beak, no teeth (along with aves)
� Ear ossicle ���� columella (ind?)
Sauropsida
Diapsida/Sauria Turtles250
Ichthyosaurs† Plesiosaurs†Archosaurs9.1K
Lepidosaurs7K
Ear ossicle ���� collumella, 3rd ind. evol.)
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Lepidosaurs
� “scaly” reptiles
� 6700 species : 4000 lizards, 2700 snakes
� Tuatara: ancestral diapsid skull
� Squamata: derived diapsid skull, hemipenes� Iguanas
� Geckos
� Snakes
� Skinks
� Gila monsters, monitor lizards, Komodo dragon
Euryapsid:
Plesiosaur
Ichthyosaur
Squamates
Snakes
Tuatara
Turtles
AvesModified
diapsid
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Sauropsida
Diapsida Turtles
Crocodiles
Archosaurs
Pterosaurs†Dinosaurs
Theropods
Dinosaurs
Ornithischians†
•Ceratopsids
•Duck-billed dino
•Stegosaurus
•Ankylosaurus
Saurischians
Sauropods†
Theropods
Dinosaurs
Ornithischians†
•-ceratops (uni, tri…)
•Duck-billed dino
•Stegosaurus
•Ankylosaurus
Saurischians
Sauropods†
•Diplodocus
•Brachiosaurus
T. rex† Velociraptor† Birds
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Sauropod and ornithischian (ankylosaurus)
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Theropods
Dinosaurs
Ornithischians†
•Ceratops (uni,tri…)
•Duck-billed dino
•Stegosaurus
•Ankylosaurus
Saurischians
Sauropods†
•Diplodocus
•Brachiosaurus
T. rex† Velociraptor† Birds
9.1K
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You know what a bird is, but…
� Extant dinosaurs
� Feathers
� Flight
� Extensive bone fusion
� No teeth
� Long flexible neck
� Hollow bones
� Extremely high metabolism
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Theropods
Sauropsida
Diapsida Turtles
Ichthyosaurs†
Crocs23
Tuatara
2
Plesiosaurs†Archosaurs Lepidosaurs
SquamataPterosaurs†Dinos
Ornithischchians† Saurischchians
T. rex† Velociraptor†
Sauropods†
Birds
9.1K
Sauropsida Diapsida
Archosaurs
Dinosaurs Saurischians
Lepidosauria
Theropods Squamata
Bird
s (aves)
Velo
cirapto
r†
T. rex
†
Sau
ropods
†
Orn
ithisch
ians
†
Ptero
sauru
s†
Cro
codilia
Ichth
yosau
ria†
Plesio
sauria
†
Snak
es
Geck
os
Iguan
as
Monito
r lizzards
Tuatara
Turtles (testu
din
a)
Tetrapods Amniotes
Sauropsida Diapsida
Archosaurs
Dinosaurs
Synapsida
Saurischians
Lepidosauria Mammalia
Amphibia
Theropods Squamata Theria Batrachian
Bird
s (aves)
Velo
cirapto
r†
T. rex
†
Sau
ropods
†
Orn
ithisch
ians
†
Ptero
sauru
s†
Cro
codilia
Ichth
yosau
ria†
Plesio
sauria
†
Snak
es
Geck
os
Iguan
as
Monito
r lizzards
Tuatara
Turtles (testu
din
a)
Euth
eria
Metath
eria
Monotrem
ata
Sailb
ack sy
nap
sids
†
Fro
gs
Salam
ader
Caecilian
s
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© George A. Lozano