What is "colossoemys"

Colossoemys is an extinct genus of alligatoroid crocodilian. It inhabited South America during the Pleistocene epoch. The genus was originally named on the basis of two large procoelous vertebrae, a pubis, and a plastral fragment (likely to be from a turtle rather than a crocodilian). The paucity of material associated with the genus has led Colossoemys to be considered a possible nomen dubium in the past.