Non-dinosaur reptiles from Judith River formation
Crocodiles
The order Crocodylia, which includes modern alligators and crocodiles, includes the only surviving archosaurs, the branch of reptiles that includes the dinosaurs, pterosaurs, and thecodonts. The crocodiles from the late Cretaceous are quite similar to modern crocodiles. The evolution of the crocodylia can be traced back to the late Triassic. Interestingly, at that time they were terrestrial animals, and bipedal in some cases.
Albertochampsa langstoni
Albertochampsa was an alligator-like reptile that inhabited Late Cretaceous swamps in Alberta. Its had a broader snout than Leidyosuchus, a common crocodilian form that was its contemporary. Note that while Albertochampsa lived during the dinosaur era, it is not a dinosaur. One obvious difference is that dinosaurs have their legs under their bodies while alligators and crocodiles' legs extend out to their sides.
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Tooth is 3/8" long |
| Formation: | Oldman |
| Epoch: | Campanian of the late Cretaceous |
Brachychampsa
Brachychampsa is different from most later alligators in having very large and rounded posterior teeth. Note that while Brachychampsa lived during the dinosaur era, it is not a dinosaur.
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Tooth is 3/8" long. |
| Formation: | Scollard |
| Epoch: | Maastrichten of the late Cretaceous |
Champsosaurus
Champsosaurus is a crocodile-like diapsid. Its exact taxonomic placement is uncertain. The Champsosaurs also survived the K-T extinction into the early Tertiary.
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Champsosaurus albertensis vertebrae from the Foremost formation. |
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Champsosaurus natator vertebrae from the St. Marys formation. |
| Order/Family: | Choristodera/Champsosauridae |
| Epoch: | late Cretaceous |