Sokatra, Gaffney & Krause, 2011

Gaffney, Eugene S. & Krause, David W., 2011, Sokatra, a New Side-Necked Turtle (Late Cretaceous, Madagascar) and the Diversification of the Main Groups of Pelomedusoides, American Museum Novitates 2011 (3728), pp. 1-28 : 3-4

Sokatra , new genus

TYPE AND ONLY INCLUDED SPECIES: Sokatra antitra , n. gen. et sp.

DISTRIBUTION: Late Cretaceous (Maastrichtian) of Madagascar.

ETYMOLOGY: Sokatra (pronounced SOO-kah-trah), Malagasy for “turtle.”

DIAGNOSIS: Member of the magnafamily Podocnemidera by possessing prootic partially covered by basisphenoid, and processus paroccipitalis of opisthotic completely covered ventrally. Distinguished from all other Pelomedusoides by short wall of bone posterior to columellae auris, medial to incisura columellae auris; foramen posterius canalis carotici interni formed by quadrate and prootic. Distinguished from all other Podocnemidera (except Kurmademydini ) by extensive temporal emargination preventing squamosal-quadratojugal and parietal-quadratojugal contacts, and exposing quadrate in temporal margin; prootic-quadrate contact. Distinguished from pelomedusids and Araripemys by deep accessory ridge on maxilla paralleling labial ridge. Additionally characterized by incisura columellae auris enclosing columellae auris and eustachian tube closed by bone, as in pelomedusids and podocnemidids; laterally open foramen jugulare posterius, as in euraxemydids; exoccipitalquadrate contact present, as in euraxemydids; and basisphenoid-quadrate contact present, as in pelomedusids, bothremydids, and podocnemidids. Lower jaw parallel sided, without any widening of the triturating surface; differs from Euraxemys , Araripemys , and pelomedusids in having a high lingual ridge forming a distinct medial margin to the triturating surface, rather than having a bladelike cross section as in Euraxemys , Araripemys , and pelomedusids. Triturating surface formed by a lingual ridge higher than labial ridge with an intervening groove or pocket.