Seymoura was an amphibian lived in the lower Permian ^{2), 3), 5)}, especially S. baylorensis was the first discovered species ⁴⁾, and its generic name and specific name are derived from the place of discovery, Seymour, Baylor County, Texas ⁴⁾.

The specimen of S. baylorensis, discovered in 1904, was 21 inches (about 53 cm) in length, excluding part of tail ⁶⁾, and the length of the adult skull was about 100 mm ⁵⁾. Based on these evidences, plus an estimate from the figure of P.233 in Williston (1911) ⁶⁾, S. baylorensis is estimated to be approximately 60 centimetres long.

Saymouria was supported by sturdy skeleton ⁴⁾ and crawled in a posture that dragged on its belly.

Seymouria presumably began and finished its metamorphosis early ^{1), 5)}. This is addvantageous in environments where the water environment cannot be maintained for a preriod of time ⁵⁾, indicating that its adult was fully adapted to its terresterial habitat ³⁾. It is presumed that Seymouria returned to the aquatic environment only during the breeding season ⁴⁾.

Seymouria was thought as an earliest reptile at first ⁶⁾.

Previously, S. baylorensis and relatively small S. sanjuannensis were found in large numbers primarily in North America, but S. sanjuanensis was also found in Germany, suggesting that Seymouria was widely distributed in northern Pangea during they were alive ⁴⁾.