Lystrosaurus lived during the Early Triassic Period 248-230 million years ago.
Lystroasurus is about 2.5 meters long and weigh over 200 pounds. A large, mammal-like reptile that resembled dinosaurs but were more closely related to mammals/humans. Their vast herds made up almost more than half of life on Earth during the early Triassic period.
Lystrosaurs were also strong swimmers. For mammal-like reptiles, they had relatively large brains but were not direct mammal ancestors overall. Lystrosaurus ate a lot of vegetation, but it also needed to form herds to get to certain places to find new vegetation.
When moving in monster-sized herds, Lystrosaurs hovered up so much vegetation that they had to constantly migrate for fresh food. They followed the seasonal rains and each year, this brought them to the edge of a huge escarpment. Sometimes, the only way for these constant animals was down through a deep ravine.
They moved mostly at night. In herds, there's only enough room to move in a single file, which left them very vulnerable. These creatures had sharp eyesight and a very good sense of smell but in cramped condition, it's hard to spot trouble ahead. Lystrosaurs were strong opponents. These animals had no social bonds.