Protechimys Schlosser, 1884

Vianey-Liaud, Monique, Comte, Bernard, Marandat, Bernard, Peigné, Stéphane, Rage, Jean-Claude & Sudre, Jean, 2014, A new early Late Oligocene (MP 26) continental vertebrate fauna from Saint-Privat-des-Vieux (Alès Basin, Gard, Southern France), Geodiversitas 36 (4), pp. 565-622 : 586-588

Genus Protechimys Schlosser, 1884

TYPE SPECIES. — Protechimys major Schlosser, 1884 by subsequent designation of Schlosser (1884).

Protechimys major Schlosser, 1884 ( Fig. 9 )

HOLOTYPE. — Left maxillary bearing DP4 to M2 (1879 XV 518, BSPG, Munich); Vianey-Liaud 1976.

TYPE LOCALITY. — Quercy, Old Collections.

EMENDED DIAGNOSIS. — (after Vianey-Liaud 1976: 55; 1998; Mödden 1993; Mödden & Vianey-Liaud 1997). Evolutionary stage more progressive than in Protechimys blainvillei ( Gervais, 1848) ( Archaeomys gervaisi Ŋaler, 1966 is a junior synonym of P. blainvillei ). Presence of a thin layer of cement even on deciduous teeth.

Lower teeth: Fusion between synclinid I and presynclinid on dp4.

Upper teeth: On P4-M3, syncline I present only in very slightly worn teeth, or missing. Syncline II absent.

MATERIAL EXAMINED. — Two p4 (one left p4 partly digested, one very damaged); one fragment of left dp4 prelobe; four complete m1-2 (three left, one right); three fragments of m1-2 trigonids, slightly worn; one right m3 heavily worn; two fragments of right maxillaries, strongly damaged (digested) bearing M1-M2, one being a very old individual; one right P4; one lingual fragment of left P4 heavily worn; one left M2 barely worn; one left M1-2 very old.

MEASUREMENTS (in mm). — Ŋe teeth being most often damaged – including at the lower half of the crown – the measurements given here are those of length and width (L × w) taken on the occlusal surface (see Vianey-Liaud 1979).

SPV01: left p4 moderately worn: 3.30 × 1.71; SVP04: right m1-2 worn: 2.56 × 2.49; SVP05: left m1-2 strongly worn: 2.14 × 2.34; SVP06: left m1-2 very little worn out: 1.91 × 1.85; SVP07: m1-2 moderately worn: 1.96 × 2.71; SVP09: right m3 heavily worn: 2.40 × 2.24; SPV012: left P4 moderately worn: 2.39 × 2.51; spv014: left M2 very little worn out: 1.66 × 1.75.

DESCRIPTION

Ŋe slightly worn lower teeth show the lingual opening of SII, and the marked angle of the two anticlinids bordering SII ( Fig. 9A, B, D ), as in P. major and P. blainvillei .

A fresh upper molar (M1-2, Fig. 9J ) shows the presence of a tiny SI, and the absence of SII. Ŋe sinus occupies the entire width of the tooth, and it is oblique, like following syncline III. Ŋe syncline IV is present and open distally, but very shallow, and must disappear quickly with wear. Ŋe base of the crown is broken, which does not allow measuring

A

1.5 2.0 2.5 3.0

the total height. Ŋe moderately worn P4 exhibits SI and SII, SIII is absent. SIV has disappeared due to wear. In the bottom of the sinus of a much abraded M1-2, some cement is noticeable.

DISCUSSION

When compared directly with M1 or M2of P.blainvillei of Rigal – Jouet1 and Le Garouillas (Quercy, France ; MP 25),theM2islargerandhighercrowned.However, it is very similar to P. major from Mas-de-Pauffié and also to a new material from Les-Milles (Bouches-du- Rhône, France ), which is also allocated to P. major .

Figures

FIG. 9. — Occlusal views of teeth of Protechimys major Schlosser, 1884, from Saint-Privat-des-Vieux (Gard; Lower Chattian, MP 26): A, fragment of right dp4, SPV03; B, left p4, SPV01; C, left m1-2, SPV05; D, left?m1-2, SPV04; E, worn left m1-2,SPV06; F, worn right m1-2, SPV07; G, left P4, SPV12; H, fragment of right P4, SPV13; I, weakly worn left M1-2, SPV14; J, strongly worn left M1-2, SPV15; K, much worn left M1-2, SPV; L, a little digested right p4, SPV03; M, moderately worn and digested right M1-M2, SPV10. Scale bar: 1 mm.