Mammal-like Reptiles

BEFORE the dinosaurs were the Mammal-like reptiles.  They were of various sizes and they were very successful.  These animals included  both carnivores and herbivores and probably omnivores as well.  Remember that omnivores can and do eat both meat and plants.  There were some of these animals that were quite large.  Many of the larger Mammal-like reptiles went extinct at the great Permian extinction.  That was when volcanic activity went wild on the Earth and over 90% of all species died off or went extinct.

Gorgonopsid in the Desert

Gorgonopsid was a top predator.  They had an 30 inch skull... or 76 cm long.  The animal was a few inches of 10 feet long . . . or about 3 meters long.  This was a huge predator with very long fangs.

Scutosaurus in the Permian Desert

Scutosaurus was another late Permian Period Mammal-like reptile.  It was an herbivore.  It ate only plants. . . probably. I suppose it might have been an omnivore instead.   It was 9.8 feet long. . . or exactly 3 meters long.  It was probably a primary source of food for Gorganopsid.  Scutosaurus possibly traveled the late Permian desert in large herds seeking food and water.  That was a time in Earth's history when all the land was together in the giant Pangea continent.  Much of the land was desert environment.  Now this is an opinion, not science fact, but I think Scutosaurus was possibly the ugliest land animal ever to live on Earth.