Sphenosuchus acutus

Sphenosuchus acutes skull from Wikipedia

Name: Sphenosuchus acutus [The sharp wedge-crocodile]

When: Early Jurassic Period, about 195 million years ago

Where: Paballon, Mount Fletcher, East Cape Province, South Africa

Claim to fame: Sphenosuchus is the classic example of "sphenosuchians," the distant relatives of crocodylians at the dawn of the age of dinosaurs. Unlike their modern relatives, these were small, long-legged, probably fast-running animals that inhabited dry-land forests. We have known the fossils of Sphenosuchus for over a century, but sadly, although its remains feature a well-preserved skull, little of the rest of its body was preserved. More recent discoveries of related sphenosuchians like Terrestrisuchus taught us about their slender long-legged build. Of course, their bodies that seem to be built for running lead us to suspect that they were warm-blooded, or nearly so.

Sphenosuchians were small. In fact, Sphenosuchus' 19 cm skull makes it a large one. Despite its length, the skull of Sphenosuchus doesn't really look like a croc's, with its tall narrow snout, but its strongly overhanging rear corners are definitely a feature it shares with modern crocs.