What it is
Two meters of amphibian. It belongs to a group called the temnospondyls. The skull alone is about as long as your forearm. Flat, wide and heavy, with the eyes set high on top of it. That is a head built to rest low at the water's edge and watch the surface. Its fossils come from early Permian rocks in Texas, where it was named in 1877.
How it ate
There are teeth along the jaw, and a second set on the roof of the mouth. Nothing about that is built for chewing. It is built for holding. The animal grabs, lifts its head, throws it back, and lets the catch slide down. That only works where prey cannot get away quickly, and in shallow water almost nothing can.
Leashed to water
For tens of millions of years, animals built like this one were the biggest hunters in the water. But an amphibian's skin has to stay damp, and its eggs have no shell, so they have to be laid in water. When the pools started going dry between rains, a grown animal could walk to the next pool. Its eggs could not.