Podocnemis bassleri Williams, 1956

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 : 31-33

Podocnemis bassleri Williams, 1956

TYPE SPECIMEN: AMNH 1662, a nearly complete skull figured by Williams (1956: figs. 1, 3–5).

TYPE LOCALITY: Rio Aguaytia, eastern Peru, about 8 ° 10 9 S, 75 ° 15 9 W fide Williams (1956).

HORIZON: Tertiary, probably Late Miocene, Contamana Group fide Williams (1956). See Gaffney et al. (1998) and Meylan et al. (2009) for further comments and references for Contamana Group chronology.

DIAGNOSIS: ‘‘Close to Podocnemis expansa , differing only in the apparently larger size, in the relationship of the internal palatal processes of the maxillae (which project abruptly dorsally and do not lie extended anteroposteriorly as in the Recent species), and in the slightly shorter relative distance from snout tip to posterior borders of the orbits’’ ( Williams, 1956: 2).

PREVIOUS WORK: Only Williams (1956) has dealt with this species. Wood and Diaz de Gamero (1971) state that this species is either ancestral to or closely related to Podocnemis expansa .

DISCUSSION: The nearly indistinguishable skulls of P. bassleri and P. expansa suggest that the age of the fossil was Williams’ main criterion for differentiating the taxa. It could be synonymized with P. expansa . In any case, this skull is the oldest definite record for the Podocnemis clade, here termed the magnatribe Podocnemidand, as ‘‘P.’’ negrii ( Carvalho et al., 2002) does not preserve any of the diagnostic characters of the genus Podocnemis and is placed as Podocnemididae incertae sedis (see below), and the specimen of Cerrajonemys is too poorly preserved to be sure of its diagnostic characters, also Podocnemididae incertae sedis (see below).

Magnatribe Erymnochelydand Broin, 1988, new rank

DIAGNOSIS: Members of infrafamily Podocnemidodda ; cheek emargination slight to absent in contrast to Podocnemis (reversed in Cordichelys and Bairdemys ); fossa precolumellaris shallow to absent, not deep (except in Erymnochelys ).

INCLUDED TAXA: Peltocephalus Duméril and Bibron, 1835 ; Erymnochelys Baur, 1888 ; Bairdemys Gaffney and Wood, 2002 ; Dacquemys Williams, 1954c ; Neochelys Bergounioux, 1954 ; Shweboemys Swinton, 1939 ; Bauruemys Kischlat, 1994 ; Stereogenys Andrews, 1901 ; Caninemys Meylan, Gaffney, and Campos, 2009 ; Turkanemys Wood, 2003 ; Neochelys Bergounioux, 1954 ; Papoulemys, Tong, 1998 ; Mogharemys , n. gen.; Cordichelys , n. gen.; Latentemys , n. gen.; Brontochelys , n. gen.; Albertwoodemys , n. gen.; Lemurchelys , n. gen.

DISCUSSION: Rather than completely reflect the cladogram within this group (see fig. 98) in the classification with new categories and taxa, we only list the paraphyletic taxa outside the tribe Stereogenyini .

Caninemys Meylan, Gaffney, and Campos, 2009

TYPE SPECIES: Caninemys tridentata Meylan, Gaffney, and Campos, 2009 .

INCLUDED SPECIES: Caninemys tridentata .

DISTRIBUTION: Late Tertiary, Miocene, of Acre, Brazil.

ETYMOLOGY: Named for the bulldog appearance of the skull and the large maxillary processes in the position of mammalian canines.

TABLE 3 Species of the Tribe Stereogenyini

Lemur- chelys? yes Stereogenys cromeri ? no Shweboemys pilgrimi no no Brontochelys gaffneyi ?? Cordichelys antiqua no no Latentemys plowdeni no no

TABLE

3

)

Continued Bairdemys winklerae yes no

( Bairdemys sanchezi yes no Bairdemys hartsteini yes no Bairdemys venezuelensis yes no Mogharemys blanckenhorni no no on base flange vertical squamosal supraoccipital Ventral Deep

DIAGNOSIS: A podocnemidid pleurodire with a well-developed processus trochlearis pterygoidei, quadrate-basioccipital contact, and a large cavum pterygoidei; unique among podocnemidids (and all other turtles) in having greatly inflated maxillae, each with a ventral, toothlike process that, together with a single process formed on the midline of the premaxillae, form a tridentate condition in the upper triturating surfaces, unique among pleurodires. The entire animal was probably smaller than Stupendemys geographicus Wood.

Caninemys tridentata Meylan, Gaffney, and