Early Permian

Arroyo Formation

Haskell County, TX, USA

Nicely ornamented skull fragment. 0.9 inch

Amphibian.

Trimerorhachis is a genus of amphibian of the extinct Order Temnospondyli.  It lived during the Early to Middle Permian and its remains have been collected in Texas, Oklahoma, and New Mexico.

Temnospondyls survived the end-Permian extinction even as most other amphibians disappeared.  They managed to survive into the Cretaceous.