Gazella cf. ancyrensis Tekkaya, 1973

Kostopoulos, Dimitrios S. & Bernor, Raymond L., 2011, The Maragheh bovids (Mammalia, Artiodactyla): systematic revision and biostratigraphiczoogeographic interpretation, Geodiversitas 33 (4), pp. 649-708 : 655-658

Gazella cf. ancyrensis Tekkaya, 1973 ( Fig. 5 )

Gazella ancyrensis Tekkaya, 1973: 118 , pl. 1, figs 1, 2; pl. 2, fig. 1.

Gazella gaudryi – Mecquenem 1925: 30, pl. 3, figs 1, 4.

Gazella cf. gracile – Bouvrain 1996: 113.

TYPE LOCALITY. — Middle Sinap, Turkey (late Miocene).

MATERIAL EXAMINED. — MNHN.F: frontlet MAR1117; right horn-core, MAR1092, 1113; left horn-core, MAR1091, 1094, 1096; isolated horn-cores, MAR1088, 1116. — HUW: skull (cranium and mandible) MCW80.

DESCRIPTION AND REMARKS

MCW80 is from the MMTT13 locality; it lacks the anterior part of the muzzle and the basioccipital whereas the horn-cores are broken just above their contact with the pedicles ( Fig. 5 ; Table 3). The braincase is rather short and bulbous with anteriorly widened lateral sides. The cranial roof curves significantly down posteriorly and moder-

Kostopoulos D. S. & Bernor R. L.

Gazella cf. ancyrensis Tekkaya, 1973

Gazella capricornis ( Wagner, 1848)

Oioceros atropatenes ( Rodler & Weithofer, 1890)

Oioceros rothii ( Wagner, 1857)

Prostrepsiceros cf. vinayaki ( Pilgrim, 1939)

Prostrepsiceros houtumschindleri

( Rodler & Weithofer, 1890)

Prostrepsiceros fraasi ( Andree, 1926)

ately bent on the face (125°). The frontoparietal suture is quite complicated and “T”-shaped. The temporal lines are smooth but visible and converge to the rear forming a low hump in the intraparietal region. The midfrontal suture is simple and not raised like a crest. The dorsal orbital rims project moderately and the orbits are large and oval-shaped. The anterior margin of the orbit is placed above the anterior lobe of M3. The ethmoidal fissure is long and narrow extended anteriorly above P4-M1 limit and equally bordered by the lacrimal, maxilla, nasal and frontal bones. The premaxillae are in contact with the nasals. The infraorbital foramina open above P3. The lacrimal fossa is large and shallow. The supraorbital foramina are small, sunken into oval-shaped pits that are placed on the base of the pedicles. The postcornual fossae are rather large and shallow. The nasals are longer than the frontals with weak lateral flanges at their anterior part and long fronto-nasal suture of inverse “V” outline. The choanae are “U”-shaped and open at the posterior limit of M3, slightly behind the lateral indentations. The horn-cores are inserted above the back half of the orbital roof, widely apart from each other and strongly inclined backwards. Their basal dimensions are similar to those of the second gazelle morphotype in MNHN.F ( Fig. 2 , Table 2), which is characterized by rather short (maximum length 90 mm) and slender horn-cores with round cross-section (mean CI = 86% at the base, n = 9; and 100% at 7 cm above the base, n = 1) and weak posterior curvature. The teeth are moderately hypsodont with high and sharp labial cusps. The upper molars have well-developed styles and ribs and lack central islets or basal pillars. The upper premolars represent c. 72% of the molar row ( Table 4). The P2 and P3 are trapezoidal shaped, weakly molarized lingually and have the paracone in mesial position. The i1 is much wider than the i2 and i3. The lower premolar row is rather long compared to the molars (c. 65%; Fig. 4, Table 5). The hypoconid of p3 and p4 is narrow, angular and protrudes labially. The paraconid is well-separated from the parastylid in both the p3 and p4, the anterior valley remains widely open, and the entoconid is fused quickly with the entostylid. The metaconid of the p3 is simple and distally directed, whereas on the p4 it is distally placed and triangular-shaped in occlusal view. The m1 bears a small basal pillar that is reduced to a knob on m2. The parastylid is weakly developed and more salient on the m3 than on the m1-m2.

Apart from the differences on the horn-core pattern, the described species is distinguished from Gazella capricornis from Maragheh in having c. 30% shorter and 10% wider opisthocranium curved down posteriorly, longer nasals compared to the skull size, “U”-shaped choanae behind the lateral indentations, longer ethmoidal fissure, stronger temporal lines, shorter molar row and highly browsing mesowear teeth pattern. Small Gazella -like horncore specimens are frequent in several early Turolian mammal sites of Anatolia but the usual absence of corresponding skulls make their taxonomic status uncertain. Bouvrain (1996) provisionally ascribed those Maragheh specimens to Gazella gracile , a species originally described from Berislava ( Ukraine) as a small subspecies of G. schlosseri Pavlow, 1913 . Although the Maragheh horn-cores have similar size with those from Berislava, their morphology differs significantly in the absence of both the characteristic basal swelling and the faintly sigmoid anterior profile, the less deep longitudinal furrows and the longer pedicles. On the contrary, the horn-core proportions of the small specimens from Maragheh match those from Garkin, Kemiklitepe D ( Turkey; Bouvrain 1994) and lower fossil levels of Samos ( Kostopoulos 2009a), suggesting the presence of a distinct small-sized Gazella species. Based on a single horn-core and some dental and postcranial remains, Tekkaya (1973) described from Vallesian levels of Middle Sinap ( Turkey) a new gazelle, G. ancyrensis with small, straight and weakly compressed mediolaterally horn-cores, having some strong longitudinal furrows on the anterior and posterolateral sides. Unfortunately, new material from Middle Sinap did not provide additional information ( Gentry 2003). By their size, insertion and overall shape, the Maragheh horn-cores are more like those of G. ancyrensis , even though they show a more accentuated posterior curvature and stronger longitudinal furrows, characters that may, however, vary significantly within a gazelle species. The features of the teeth allocated by Tekkaya (1973) to G. ancyrensis also fit those of the Maragheh gazelle,

Kostopoulos D. S. & Bernor R. L.

albeit the latter shows somewhat longer premolar row comparatively to the molars; nevertheless, both samples are very poor for safe conclusions. We suggest therefore referring the small gazelle from Maragheh to as Gazella cf. ancyrensis .

Figures

FIG. 5. — Gazella cf. ancyrensis Tekkaya, 1973 cranium (MCW80) from Maragheh in lateral (A), dorsal (B) and ventral (C) views. Scale bar: 5 cm.

FIG. 2. — Bivariate plots of basal horn-core dimensions in Gazella Blainville,1816 from Maragheh (transverse diameter [TD] against anteroposterior diameter [APD]). KUE data from Watabe (1991).