Around 155 million years ago in what is now Wyoming, a crocodile relative clamped its jaws around a thrashing animal and dragged it below the water's surface, and the ancient reptile could still breathe comfortably as its prey slowly drowned.
That's because the croc had specialized structures that prevented water from flowing through its mouth and into its airway. This feature is known in modern crocodilians — crocodiles and their close relatives — and scientists recently identified the same mechanism in a newly described species of croc cousin that lived during the Jurassic period (201.3 million to 145 million years ago).
This is the earliest evidence of crocodilian adaptations for submerging their heads (and prey) underwater while still being able to breathe through nostrils on top of their snouts; this ability is an important part of the group's deadly feeding habits today, and may have helped crocodilians survive the Cretaceous extinction that wiped out most of the dinosaurs.
