Comtia Vianey-Liaud, 2014

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 : 602-604

Genus Comtia Vianey-Liaud , n. gen.

DIAGNOSIS. — Ŋat of the type-species.

SPECIES INCLUDED. — C. bernardi n. sp.; ṙ C. giganteus ( Freudenberg 1941) .

Comtia bernardi Vianey-Liaud , n. sp. ( Fig. 15A )

ETYMOLOGY. — Dedicated to the late Bernard Comte.

HOLOTYPE. — Right M ṙ1 ( SPV190 ), Coll. UM2 .

TYPE LOCALITY. — Saint-Privat-des-Vieux (Gard, France ), lower Chattian ( MP 26).

DIAGNOSIS. — Squirrel of large size (M1-2: L × w = 3.4 × 4.02 mm); lingual flank of the tooth higher than the labial one. Cusps high and acute (parastyle, paracone, mesostyle, metacone, small hypocone and protocone); one small paraconule, two metaconules stronger than the paraconule; straight protoloph and metaloph higher than the anterior and posterior cinguli; enamel slightly wrinkled all along the cusps and lophs as well as in the basins. Differs from:

– Oligopetes Heissig, 1979 , in the absence of postparacrista connected to the mesostyle and the well marked paraconule and metaconules;

– Paracitellus Dehm, 1950 , in the connection of the paraloph and metaloph to the protocone, and in the absence of labial connection between parastyle-paraconemesostyle-metacone and posteroloph;

– Miopetaurista Kretzoi, 1962 , or Forsythia Mein, 1970 , in its non-crescentic cusps;

– Blackia Mein, 1970 , in the presence of conules, and the less wrinkled enamel.

MATERIAL AND MEASUREMENTS (in mm). — A single isolated right upper molar has been collected at Saint- Privat-des-Vieux. SPV 190 Mṙ1: L × w = 3.4 × 4.02, protocone height = 2.48, paracone and metacone height = 1.95.

DESCRIPTION

Ŋis unworn molar has well-individualized cusps. Ŋe anterior cingulum runs from the base of the protocone to the anterior flank of the paracone which it is connected by a low ridge.It has a bulbous parastyle. Ŋe hypocone is small, but well protrud - ing at the lingual end of the posterior cingulum. Ŋe hypocone is connected to the distal end of the protocone through a low endoloph. Ŋe metacone is a little smaller than the paracone. Ŋe mesostyle is also bulbous, developed in the middle of the valley between the two labial cusps. It extends lingually by a short mesoloph. Ŋe protoloph is connected transversely to the anterior arm of the protocone. It displays one well distinct protoconule, and a weak other one, the more pronounced being the most labial. Ŋe metaloph is connected to the rear of the protocone in front of the endoloph anterior end. It is slightly oblique relative to the protoloph. It has two metaconules, wider than the protoconules. Ŋe labial metaconule is the most marked. Both lophs with their conules are lower than the main cones and styles, which are prominent. A short and low spur descends from the top of the protocone labially in the median valley of the tooth.

Ŋe entire crown is relatively high, the lingual flank of the protocone + hypocone being the highest. Enamel is slightly crenulated on the surface of the valleys and transverse lophes, but without clear-cut crestules.

DISCUSSION

Even if the material is restricted to one tooth, we decided to describe a new taxon because it is easy

to distinguish this form from the other large Oligocene and lower Miocene squirrels. One lower m3 of close size (L = 4.07 mm, l = 3.41 mm) is known from Pech Desse (Quercy, MP 28a), but its crown is clearly lower (H of metaconid = 1.79 mm, strongly overhanging the other cuspids and the low talonid basin) and the cuspids less acute.

Another large sciurid is summarily reported as “ Sciurus ” giganteus in Freudenberg (1941) and Werner (1994) from the lower Miocene of Eckingen (Southern Germany). Only 2 m 3 (4.20 × 4.06 and 4.09 × 4.00) and 1 M3 (3.53 × 3.74) are known.Ŋis species shares wrinkled enamel with Comtia bernardi Vianey-Liaud , n. gen., n. sp. Ŋe wrinkles seem more numerous in the former. It is difficult to compare the M3 of Freudenberg with our M1-2, mainly the height of the protocone and other cusps, the shape and number of buccal cusps and their mesio-distal connections, the occurrence of conules.Ŋis species is tentatively included in the genus Comtia n. gen. We keep provisionaly the two species: bernardi and giganteus , waiting for more material and information.

A slightly smaller upper teeth is described as ṙ Ratufa sp. from Ulm-Westtangente by Werner (1994: 171). It differs from the M1-2 from Saint- Privat-des-Vieux in its clearly lower crown, its less prominent cusps, especially the hypocone, the absence of metaconules, its smooth enamel.

Some teeth of a large Sciuridae from an Oligocene Turkish locality (Kocayarmalar) have been attributed to the flying squirrels Petauristinae Brandt, 1855 and with doubt to Miopetaurista , by de Bruijn & Ünay (1989). Ŋorington et al. (2005) discussed the difficulties to identify fossil flying squirrels on the basis of dental morphology alone, considering many cases of convergent evolution. Ŋerefore, we assign the species of Saint-Privat-des-Vieux, represented by a single tooth, to the family Sciuridae without further details.

Slightly smaller than the one of Saint-Privat-des- Vieux, the teeth from Kocayarmalar exhibit some similarities to it, such as the central mesostyle, separated both from paracone and metacone, the lingual mesoloph indicated by an outgrowth in the central basin (here drawn lingually by a spur from the protocone and labially by a marked ridge from the mesostyle) and by the low hypocone. Ŋe strong wear on teeth from Kocayarmalar makes them difficult to compare. However, some significant differences can be pointed, highlighting the strong metaconule, while the labial swellings of the metaloph are lower, in contrast to what occurs at Saint-Privat-des-Vieux. Despite the wear, accessory ridges from the mesostyle and metacone are well marked and the enamel surface is smooth (de Bruijn & Ünay 1989: figs 10, 11). Ŋere are no particular indications on the height of the crown for the Turkish material.

Otherwise, being of the same size as the large Miocene Miopetaurista and Albanensia Daxner- Höck & Mein, 1975, the tooth from Saint-Privatdes-Vieux differs from them by a bunodonty more pronounced, the hypocone shorter, the protoloph and metaloph less convergent, and the crenulations of enamel seemingly more attenuated.

NOMENCLATURAL REMARK

Ŋis new species must be referred to “ Comtia bernardi Vianey-Liaud, 2014 ”, following the article 50.1 and the “recommendation 50A concerning multiple authors” of the International Code of Zoological Nomenclature (ICZN 1999: 52, 182).

Figures

FIG. 15. — A, Comtia bernardi Vianey-Liaud, n. gen., n. sp., right M1-2, from Saint-Privat-des-Vieux (Gard; Lower Chattian, MP 26), SPV190, occlusal view; B-D,? cf. Aplodontidae indet. B, SPV187, anterior fragment of lower molar: B1, occlusal, B2, mesial, B3, lin- gual,B4, distal, B5, labial;C, SPV188,posterior? fragment of lower molar: C1, occlusal,C2, mesial,C3, lingual,C4, distal;D, SPV189, fragment of upper tooth: D1, occlusal, D2, lingual, D3, labial, D4, distal. Scale bars: A, 1.5 mm; B-D, 1 mm.