Gafsachelys moularensis Bergounioux, 1955a

GAFFNEY, EUGENE S, TONG, HAIYAN & MEYLAN, PETER A, 2006, EVOLUTION OF THE SIDE-NECKED TURTLES: THE FAMILIES BOTHREMYDIDAE, EURAXEMYDIDAE, AND ARARIPEMYDIDAE, Bulletin of the American Museum of Natural History 300 (300), pp. 1-698 : 114-115

Gafsachelys moularensis Bergounioux, 1955a

TYPE SPECIMEN: ‘‘G1’’, probably in the collection of the Mines de Moularès, Tunisia, a partial shell figured in Bergounioux (1956: pl. 10, fig. 1).

DISCUSSION: Bergounioux (1956: fig. 21) did provide some comic relief for hardpressed paleontologists when he named a new species Gafsachelys moularensis by describing a turtle shell backwards ( Bergounioux, 1956: fig. 21; see also G. neurrirregularis , fig. 24), with the pygal labeled nuchal and vice versa (showing that all turtle shells look alike, no matter what direction they are going). This was only to be expected from the author of the world’s oldest turtle, Archaeochelys pougeti Bergounioux, 1938 , a Permian concretion.

CURRENT STATUS: Nomen dubium.

Gafsachelys phosphatica Stefano, 1903

TYPE SPECIMEN: A partial shell steinkern in the MNHN, formerly in L’Ecole Nationale Supérieure des Mines de Paris.

DISCUSSION: Stefano (1903) was the first to study turtle remains from the Ypresian of Gafsa, Tunisia. In 1903 he created Gafsachelys phosphatica on the basis of a partial shell in the collection of ‘‘Ecole Nationale Supérieure des Mines de Paris’’ and placed it in the Chelydridae . Bergounioux (1952) correctly rejected the species phosphatica (but illegally) and created neurirregularis as the replacement ‘‘ type species’’ of the genus Gafsachelys . He placed this genus in ‘‘Family Incertae sedis’’ in Cryptodires. Bergounioux (1956) erected another species of Gafsachelys , G. moularensis , and included Gafsachelys in the family Eusarkiidae , created by the same author in 1952 ( Bergounioux, 1952, 1955b, 1956). Moody (1972) rehabilitated Gafsachelys phosphatica Stefano, 1903 and characterized it by seven continuous neurals. He assigned four more shells in the Metlaoui Museum, Tunisia, to this species. Broin (1977) reexamined the type specimen of Gafsachelys phosphatica and confirmed that it does have the continuous series of neurals. She pointed out, however, that this specimen cannot even be assigned to Pelomedusoides with certainty since cheloniids are also present in the same locality, and the latter also have narrow neurals. She rejected Gafsachelys phosphatica since it is based on an indeterminate specimen. Moody and Buffetaut (1981) reaffirmed their recognition of the three monotypic genera, Gafsachelys , Crassachelys , and Eusarkia. Gafsachelys (and Eusarkia and Crassachelys ) have been synonymized with Taphrosphys by Antunes and Broin (1988), Broin (1988), and Lapparent de Broin (2000a).

Examination of the holotype of Gafsachelys phosphatica Stefano by us supports Broin’s original (1977) assessment that the holotype is not diagnosable. The dubious assignment of better specimens to this taxon by later authors does not make the holotype any more diagnosable or the name any more available.

CURRENT STATUS: Nomen dubium.

Naiadochelys ingravata Hay, 1908

TYPE SPECIMEN: AMNH 6078.

DISCUSSION: The type and only known specimen of this taxon is the posterior part of a left xiphiplastron, AMNH 6078 ( Hay, 1908: fig. 133). It was given to an AMNH archeologist working at Chaco Canyon, New Mexico, in 1900 by Native Americans and is presumably from the San Juan Basin, Late Cretaceous–Eocene. It agrees closely in size, shape of the ischiac scar, and smooth external surface with YPM 3608 Chedighaii (formerly Bothremys ) barberi . Unfortunately, these features are widespread in Pelomedusoides and inadequate to objectively identify AMNH 6078. This taxon is considered to be incertae sedis at the level of Pelomedusoides, as these features occur in both Bothremydidae and Podocnemididae . However, if this fragment did come from the San Juan Basin, it is possible that it belongs to Chedighaii hutchisoni , presently known only from a skull.

Broin (1988) synonymized Naiadochelys ingravata with Taphrosphys sulcatus , but Taphrosphys is unique among pleurodires in having a small, circular ischiac scar, quite different from the large triangular scar in Naiadochelys and in most other pleurodires. Naiadochelys ingravata also has a smooth external surface texture, different from the pebbled surface of Taphrosphys .

CURRENT STATUS: Nomen dubium.

‘‘ Najadochelys ’’ (sic) patagonica Staesche, 1929

‘‘ Najadochelys ’’ (sic) major Staesche, 1929

TYPE SPECIMEN: Unclear. DISCUSSION: In keeping with the tradition of naming useless fragments, Staesche (1929) described a collection of fragments from the Late Cretaceous (now Paleocene) of Argentina as containing the new taxa ‘‘ Najadochelys ’’ patagonica and ‘‘ N.’’ major . The reasons for identifying these (and misspelling the generic name) with Hay’s fragment are unclear, but presumably one unidentifiable taxon deserves a few more. Broin (1977: 31) suggested that these were ‘‘restes d’un ancien Chélide´’’ ( Broin, 1977: 31), which was repeated in Broin and Fuente (1993). The Staesche material, as figured, is nearly identical with fossil chelids in the Museo de la Plata seen by one of us (E.S.G.), and we concur with this identification.

CURRENT STATUS: Nomen dubium for both species.

‘‘ Podocnemis ’’ lata Ristori, 1895

TYPE SPECIMEN: A partial carapace plus some fragments, uncataloged, supposedly in a museum in Italy, current whereabouts unknown.

DISCUSSION: The type and only known specimen is from the Miocene of Malta, described and figured by Ristori (1895). The carapace is unusual, but not unique, in having costals 6–8 meeting on the midline, but otherwise it has no distinguishing features. Lapparent de Broin and Werner (1998) and Lapparent de Broin (2001) identified it as a bothremydid, but gave no reasons, nor did they indicate if they had seen, or even found, the specimen, which we have not. The figured carapace is similar to bothremydids like Rosasia and Chedighaii barberi in having (probably) a posterolaterally expanded shell and a similar shell margin. However, these features are not unique to bothremydids. This shell could be a podocnemidid or a bothremydid, but it is inadequate as a basis for extending the range of the Bothremydidae into the Miocene, as claimed by Lapparent de Broin and Werner (1998). The original description is detailed and there is a good figure, but the specimen consists only of the posterior two-thirds of a carapace and is not sufficient to distinguish it as a unique taxon.

CURRENT STATUS: Nomen dubium.

Sokotochelys umarumohammedi Halstead, 1979b

TYPE SPECIMEN: ‘‘ Sokoto State Government Palaeontological Collection’’ SOSG no. 1. Probably no longer exists. DISCUSSION: See below.