SLAUGENHOPIA TEXENSIS (AMPHIBIA: TEMNOSPONDYLI) FROM THE PERMIAN OF TEXAS IS A PRIMITIVE TUPILAKOSAURID

The temnospondyl amphibian Slaugenhopia texensis from the late Leonardian (Early Permian) San Angelo Formation of Knox County, north-central Texas, was described as a trimerorhachid by Olson. Restudy of the material shows it to be a member of the Tupilakosauridae and thus a more derived member of the clade Dvinosauria than the trimerorhachids. It possesses derived character-states of the Tupilakosauridae, including the reduced postfrontal, the postorbital-parietal suture, and the posterior pterygoid notch, but lacks the embolomerous centra of the Triassic tupilakosaurids. It is the earliest and most primitive tupilakosaurid and extends the history of the group back to the end of the Early Permian.