A cross between a dog and a lizard, cynognathus was one of the top predators of its time. These fierce animals hunted in packs, using their sharp teeth and powerful bodies to drag down prey. Cynognathus had so many similarities to mammals that scientists believe that this creature gave rise to all modern mammals.
More than a Mouthful: This was one of the first animals with specialized teeth. Two pointed canines stabbed into a victim, and the rest were sharp incisors that sliced through meat.
Pack Attack: Cynognathus was relatively small, but that didn't stop it from tackling huge prey. Attacking in groups, one beast would clutch the victim's throat in its jaws while the others tore away at the prey's back and stomach.
A Breed Apart
Though cynognathus was a reptile, it had many features of modern-day mammals. Only mammals have long canine teeth like those seen in cynognathus fossils, and the prehistoric beast's skin was likely covered in fur, also a trait of mammals. Plus, its legs were positioned underneath its body rather than out to the sides, unlike most reptiles of the time. Paleontologists speculate that cynognathus is the original ancestor of all mammals.
Short & Stocky: The well-muscled cynognathus was an active hunter. This meant that the creature, unlike most reptiles, had to eat a lot to give it strength. Fur trapped body heat to keep the beast warm, allowing it to hunt on cold nights.
Big Head: Cynognathus' head was unusually large. Its 12-inch skull accounted for almost 20 percent of its entire body length.
Cynognathus lived about 245-230 million years ago, during the Triassic Period.