Shweboemys Swinton, 1939

Gaffney, Eugene S., Meylan, Peter A., Wood, Roger C., Simons, Elwyn & De Almeida Campos, Diogenes, 2011, Evolution Of The Side-Necked Turtles: The Family Podocnemididae, Bulletin of the American Museum of Natural History 2011 (350), pp. 1-237 : 55-56

Shweboemys Swinton, 1939

TYPE SPECIES: Shweboemys pilgrimi Swinton, 1939: 548 .

INCLUDED SPECIES: Shweboemys pilgrimi Swinton, 1939 .

DIAGNOSIS: A podocnemidid of the Tribe Stereogenyini known from the skull; uniquely possessing an elongate basisphenoid that has very little palatine contact and very narrowly separates the pterygoids, which are almost in contact, in contrast to the longer basisphenoid, which broadly contacts the palatines in Stereogenys ; pinched snout in contrast to Infratribe Bairdemydita ; medial edges of palatal cleft parallel in contrast to the Infratribe Bairdemydita ; basioccipital shorter than in all other Tribe Stereogenyini except Stereogenys ; palatine with dorsal process in septum orbitotemporale that contacts parietal as in Stereogenys and in contrast to all other Tribe Stereogenyini .

DISTRIBUTION: Burma, Pliocene or Pleistocene.

DISCUSSION: This genus was erected by Swinton in 1939 on the basis of a single skull from Burma. Swinton recognized that it was a ‘‘pelomedusid’’ sensu lato and compared it with Podocnemis and Stereogenys . He was the first to determine the unique nature of the palatal cleft and recognize that this unique cleft also occurred in Stereogenys .

Wood in 1970 identified a second skull of Shweboemys pilgrimi (BMNH R.8432) using Swinton’s description and new photographs of the type specimen from the Geological Survey of India. Wood (1970) also moved Andrew’s ‘‘ Podocnemis ’’ antiqua to Shweboemys on the basis of the secondary palate and described a new species of Shweboemys , S. gaffneyi . At that point, the genus (essentially equal to our tribe Stereogenyini ) consisted of three species: pilgrimi, antiqua , and gaffneyi .

In 1977, Jain described a new species of Pelomedusoides, pisdurensis, from the Late Cretaceous of India, first ( Jain, 1977) assigning it to ‘‘ Carteremys ’’ then to Shweboemys ( Jain, 1986) . The change in generic assignment by Jain was prompted by the suggestion of one of us (E.S.G.) based on the published figures in Jain (1977). We still have not had an opportunity to examine the specimens, but, again based solely on the published figures, pisdurensis does not belong in Shweboemys and probably does not belong in the Tribe Stereogenyini . The figures of the ventral surface of the skull (supplemented by other photographs sent to E.S.G. by Jain) do show a broad palate but one that lacks the distinctive cleft that we argue is diagnostic for this group. From the photographs it is also difficult to be sure that the skull has the cavum pterygoidei diagnostic of the Podocnemididae . Therefore, we provisionally exclude pisdurensis from Shweboemys and the Tribe Stereogenyini and place it incertae sedis without generic assignment, within the Pelomedusoides, pending further study.

In the present study we remove Shweboemys gaffneyi Wood to a new genus, Brontochelys . We also remove Shweboemys (Podocnemis) antiqua (Andrews) to another new genus, Cordichelys . As we currently recognize Shweboemys it consists only of the type species, Shweboemys pilgrimi Swinton. The increase in taxonomic diversity in the podocnemidids with a secondary palate developed in this paper is consistent with current practice in Recent turtles, particularly Pelomedusoides.