Deinosuchus
As a Deinosuchus you would wait motionless in the warm coastal swamps of Cretaceous North America – and the animals that came to drink would include dinosaurs.
On both shores of an inland sea
Deinosuchus lived about 82 to 75 million years ago, in the Campanian stage of the Late Cretaceous. North America was then divided by the Western Interior Seaway, and Deinosuchus fossils turn up on both sides: in Texas, Montana and Utah in the west, and in Georgia, Alabama and the Carolinas in the east. Its world was one of estuaries, coastal marshes and lagoons. It was a crocodylian – a relative of today’s alligators and crocodiles – not a dinosaur, although it hunted them.
How big?
Size estimates vary with species and method, but large individuals probably reached around 8–10 metres and several tonnes. The skull was broad, with a strange bulbous swelling at the tip of the snout whose function is unknown. A 2022 study also found that, despite its alligator-like appearance, it sat on its own branch of the crocodylian family tree. Growth rings in its bony armour suggest it kept growing for decades, taking around 35 years to reach its great size.
What was for dinner
The front teeth were for gripping, but the back teeth were blunt and robust – good for crushing the shells of turtles, which are common in the same rocks and sometimes bear its bite marks. Fossil bones of duck-billed dinosaurs and even tyrannosaurs from Texas and the eastern states carry tooth marks matching Deinosuchus. Whether those were kills or scavenged carcasses is hard to tell, but an ambush at the water’s edge, followed by the famous ‘death roll’, is a plausible picture.
An adult would have had few enemies. Young ones, like baby crocodiles today, would have been eaten by fish, birds, other crocodylians and probably small dinosaurs. Survive that phase and this could be a long life.
