Seymouria is a seymouriid seymouriamorph amphibian from the Cisuralian-Guadalupian of the United States of America and Germany. It was named in 1904 by Ferdinand Broili. It was another of the missing links between amphibians and reptiles; in fact, it had so many reptilian features that it was actually considered to be a reptile.
Physiology
Seymouria had a build that reflected its relations and evolution. It was a lizard-like animal with 4 legs, a long, broad, fin-less tail, a broad body, and a long head with big jaws. Its body would have been covered in scaly skin.
Diet
Seymouria was a predator, feeding mainly on insects and smaller amphibians, and sometimes subsisting on reptile and synapsid eggs. Its teeth were small yet sharp, and were used to get a hold of struggling prey as the amphibian swallowed them whole.
Ecology
Despite its amphibian classification, Seymouria was more adapted to land, as its legs were long and muscular, and the structure of its ears would have worked best out of water. As well as this, it would have been able to excrete excess salt out of its body through its nose, similar to modern reptiles. Along with that, male Seymouria had thick skulls used for ramming into rivals during mating season; after the mating process, females would return to the water to lay their eggs. There, the eggs would hatch into aquatic tadpoles, which would hunt in the water until they would gain the strength to walk onto land.
In popular culture
Seymouria was featured in the 2nd episode of the 2005 documentary Walking with Monsters, where it is shown as an ovivorous carnivore that spied on the nest of a female Dimetrodon, waiting for the predatory pelycosaur to get caught off guard so it could eat her eggs. When it finally got the chance to do so, it got eaten by a male Dimetrodon that came near the nest.