One of the earliest crocodilians were known as Chasmatosaurs, which had large hooked upper jaws. They swam through the waters of the early Triassic, preying on many different creatures. One such individual was Proterosuchus, a fairly large and dangerous Chasmatosaur that gathered in groups for the annual Lystrosaurus migration, like Nile crocodiles in modern Africa. They were very strong and proficient predators.

Basic info

Meaning of name: Proterosuchus means "primitive crocodile".

Time of existence: Proterosuchus lived in the early Triassic, 252.17 million to 247.2 million years ago.

Diet: Proterosuchus was a carnivore, and floats of them would stay in one area to wait for the annual Lystrosaurus migration, as they fed on Lystrosaurus and killed them by biting and drowning them. They also fed on Euparkeria.

A float of Proterosuchus

Threats: Proterosuchus had no true known threats. Its possible that they could suffer from climate change, but even that cannot be confirmed.

Size: Proterosuchus could grow anywhere from 4.9 to 7.2 feet long.

Attributes: Proterosuchus, being a crocodilian, was a very strong swimmer, and also seemed to be able to go for a long time without food, as some would wait for an entire year before eating again after the Lystrosaurus migration. However, their most important attribute was their hooked upper jaw, which allowed it to grab prey, and once it had a hold, prevent it from escaping.

Proterosuchus swimming

Appearances in the Walking with... series

Walking with Monsters

Proterosuchus appears swimming in the opening.

Proterosuchus in the opening

Episode 1-Water Dwellers

Proterosuchus is only briefly seen in the opening synopsis, where it is seen dragging a Lystrosaurus underwater.

Episode 2-Reptile's Beginnings

Proterosuchus only makes a brief appearance at the end of the credits, where one is seen swimming.

Episode 3-Clash of Titans

Proterosuchus appears in the Triassic segment of the episode, where they are only referred to as "Chasmatosaurs". One is first seen opening its hooked jaws and hissing while basking on the riverside. It is revealed that these early crocodile relatives have a specially adapted overbite so that they can get a permanent grip on prey. It is revealed that they have gathered in a float, which they do not usually do, waiting for the arrival of the migrating Lystrosaurus. A large number hiss at each other, clearly annoyed by each other's presence. One is seen basking, and it is approached by a Euparkeria, who is interested in the dragonfly that has landed on its teeth. However, the insect flies away, and the Proterosuchus attempts to snap up the Euparkeria, but fails and runs after it. Eventually, the Chasmatosaurs begin to go into the water, sensing the approaching reptiles. Some of them haven't eaten in a year, since the last migration. The Lystrosaurus soon arrive, and the Proterosuchus are there to greet them with open jaws. Eventually, one Lystrosaurus dives into the water and begins to swim.

A Proterosuchus basking

A Proterosuchus is seen approaching as more Lystrosaurus get into the water, ready to begin their attack. One is seen popping its head out of the water and watching the first Lystrosaurus clamber onto land. This is of course no loss to them-there is plenty more meat coming. Another Proterosuchus is seen eyeing a large group of swimming Lystrosaurus, and the predators begin to move towards the group, with one still being visible from above the water. However, it quickly dives under, and is then seen grabbing a Lystrosaurus by the neck and dragging it under. Another Chasmatosaur is seen approaching and struggling to drag a Lystrosaurus down. Yet another is shown, this time seriously injuring the Lystrosaurus, as indicated by the blood in the water around the predator. Another is briefly seen gripping onto a Lystrosaurus, and we see another, once again surfacing from a bloody puddle, holding a Lystrosaurus who is attempting to escape, only to drag it back under. Another Proterosuchus is briefly seen watching another drag another dying Lystrosaurus into the reddened river. Despite their ravaging of the herd, most of the Lystrosaurus make it to the other side, and once eating their fill, the exhausted predators leave, with one being seen presumably swimming to shore. Later, a Proterosuchus is briefly seen watching a Euparkeria scavenge off a dead Lystrosaurus, before the small reptile evolves into a dinosaur. The Chasmatosaur growls at the giant a few times, before we are given a preview of what is in store for Euparkeria's ancestors.