Prionochelys

Prionochelys is an extinct genus of pancheloniid from the Mooreville Chalk and Eutaw Formations of Alabama. It consists of a single species, P. matutina.

Taxonomy
Prionochelys was originally assigned to the family Toxochelyidae. A 2018 paper found it to be on the stem of Cheloniidae, the family to which most modern sea turtles belong, forming a monophyletic grouping with Ctenochelys and Peritresius. In 2019, Gentry et al. assigned Prionochelys to the extinct Ctenochelyidae family. A cladogram from their analysis: