Chupacabrachelys complexus, n. gen. n. sp., is an unusual bothremydid pleurodire of the tribe Taphrosphyini found in the Campanian Aguja Formation in the Big Bend region of West Texas. The type example is one of the most complete bothremydid specimens known. Its skull and lower jaw are very narrow, triangular, and dorsoventrally compressed, with the coronoid process posterior to midlength of the jaw. The orbits are elongate anteroposteiorly with narrow extensions along the maxilla-prefrontal sutures, and rugose maxillary projections at the anterolateral corners of orbits. Its reduced temporal emargination, weak posteroventral flange on the squamosal, weak lateral extension of the squamosal along the quadrate suture, and posteroventral knob on opisthotic suggest affinity with Taphrosphyini. The shell has six neurals and a nuchal with sharp midline embayment, and is nearly identical to those of Chedighaii and Bothremys. Chupacabrachelys provides additional evidence for the dramatic evolutionary radiation of bothremydid turtles in tropical paralic environments during Late Cretaceous time.