Gazella capricornis ( Wagner, 1848 )

Kostopoulos, Dimitrios S. & Bernor, Raymond L., 2011, The Maragheh bovids (Mammalia, Artiodactyla): systematic revision and biostratigraphiczoogeographic interpretation, Geodiversitas 33 (4), pp. 649-708 : 652-655

Gazella capricornis ( Wagner, 1848) ( Fig. 3 )

Antilope capricornis Wagner, 1848: 368 : pl. 4, fig. 6.

Gazella deperdita – Rodler & Weithofer 1890:14. — Mecquenem 1925: 30, pl. 3, figs 2, 5, 8. — Bernor 1978: 78; 1986: table 1. — Solounias 1981: table 4. — Bernor et al. 1996: table 10.2.

TYPE LOCALITY. — Pikermi, Greece (late Miocene).

MATERIAL EXAMINED. — MNHN.F: Frontlet MAR1031 ( Mecquenem 1925: pl. III, fig. 2 as G. deperdita ), MAR1033; part of skull MAR1034 (old number 8044; Mecquenem 1925: pl. III, fig. 1 as G. gaudryi ); occipital part of skull MAR1062; right horn-core, MAR1097, 1114, 1392, 1393; left horn-core MAR1032, 1090, 1095, 1098, 1099, 1101, 1111, 1112, 3172; part of horn-core 1088, 1089, 1105, 1116; P2-M3, MAR1028 ( Mecquenem 1925: pl. III, fig. 5 as G. deperdita ); lower tooth row with p2-m3, MAR1027 ( Mecquenem 1925: pl. III, fig. 8 as G. deperdita ), MAR1843. — HUW: skull MMTT13/2583 ( MCW 59).

DESCRIPTION AND REMARKS

Accounting for the number of the Maragheh Gazella species and their taxonomic status remain debatable due to the puzzling alpha taxonomy in late Miocene representatives. Rodler (1885) recognized the occurrence of G. deperdita (Gervais, 1847) within the Maragheh fauna while Pohlig (1886) reported G. brevicornis (Roth & Wagner, 1854) at Maragheh. Later on, Rodler & Weithofer (1890) recognized both of these taxa as occurring at Maragheh and introduced a new taxon, G. capricornis , a name that, however, was pre-occupied by Wagner (1848) for the Pikermian gazelle. Mecquenem (1925) described G. brevicornis , “ G. capricornis ” Rodler & Weithofer, 1890 and G. gaudryi Schlosser, 1904 (valid name G. pilgrimi Bohlin, 1935 ) from Maragheh. Pilgrim & Hopwood (1928) put in synonymy G. brevicornis with G. capricornis and proposed the new species name G. rodleri for the Maragheh “ G. capricornis ”. Bernor (1978) and Bernor et al. (1996) referred to a single gazelle species, G. deperdita / capricornis implying either impossibility of distinction or synonymy between these two species. Watabe (1990) refrained from making species identifications for KUE gazelle specimens. Bouvrain (1996) noted that “plusieurs espèces de gazelles sont présentes dans le matériel de Maragha” and attributed the smaller horn-core specimens in the Paris collection to Gazella cf. gracile ( Korotkevich, 1976) . Apart from “ Gazella ” rodleri that will be discussed later, the sample currently under study from Maragheh includes 36 cranial and isolated horn-core specimens.Two basic horncore morphs are indeed present within the Paris sample but their dimensions show a continuous range that prohibits ( Fig. 2 ; Table 2) a sharp distinction between them based on horn-cores alone. Nevertheless, two almost complete skulls in HUW (MMTT13/2583 and MCW80-next section) allow a better taxonomical resolution.

MMTT13/2583 ( Fig. 3 ; Table 3) is slightly deformed and lacks the anterior portion of the maxilla and premaxilla. MAR1034 ( Mecquenem 1925: pl. III, fig. 1; Table 3) is badly damaged but still retains most of the cranial roof and maxillae and the proximal part of the horn-cores. MAR1062 preserves only the occipital region but it could belong to the same individual as MAR1034. The braincase is fairly long and widens slightly anteriorly; its top is gently convex in a lateral profile, set at a steep angle to the occipital surface (c. 120°), and gently bent on the face (c. 145°). The midfrontal suture is slightly constricted between the horn-cores. The temporal lines are visible only in their anterior part, directly behind the orbits. The dorsal orbital rims are moderately wide. The orbit is large and round with its anterior margin above the back lobe of M2. The postcornual fossae are usually large, oval-shaped and deep. The supraorbital foramina are placed in small triangular depressions close to the base of the pedicles. The infraorbital foramina open above P3. The lacrimal fossa is large, round, moderately deep with well-marked ventral rim and close to the orbit. The ethmoidal fissure is short and narrow. The nasals are shorter than the frontals, weakly domed in lateral profile, without lateral flanges, wider posteriorly than anteriorly, with bilobed fronto-nasal suture, and broadly pointed anteriorly. The premaxillae are in contact with the nasals. The occipital is semicircular shaped and faces partly laterally. The external occipital crest is weak. The mastoid is narrow and faces mostly posteriorly. The foramen magnum is approximately square-shaped and wider than high. The occipital condyles are rather small. The basioccipital is moderately long with strong, ridge-like posterior tuberosities perpendicular to the sagittal plane and small to moderate anterior tuberosities well-localized and developed mostly ventrally. A thin crest runs the length of the

Kostopoulos D. S. & Bernor R. L. TABLE 2. — Horn-core measurements (in mm) of Gazella Blainville, 1816 species from Maragheh. For abbreviations see text.

basioccipital bone. The auditory bulla is large and bulbous. The external auditory meatus is large and almost round. The palatine foramina open at the level of the anterior lobe of M3. The choanae are “V”-shaped and open at the posterior limit of M3 and slightly anteriorly to the lateral indentations. The pedicles are rather short. The horn-cores are moderately long (maximum 135 mm) inserted above the orbits and set well apart at their bases. They are fairly curved (index Lhc / Hhc [ Kostopoulos 2005]: 1.06-1.23, n = 9) and weakly inclined backwards, showing moderate mediolateral compression throughout their length (mean compression index, CI = 81% at the base, n = 29; mean CI at 7 cm above the base = 87%, n = 12) (Table 2). The horncore divergence is usually of the “V”- type (at about 45°), although in a few specimens this angle may be wider (MAR1037). The parallel horn-cores seen on the specimen MAR1033 are obviously due to distortion of the frontals, whereas MAR1031 does not differ enough from the basic morphotype to be excluded (contra to Bouvrain 1996). The longer axis of the horn-core base trends anteroposteriorly, forming an acute angle with the sagittal plane. Longitudinal furrows run along the antero-medial and posterior faces of the horn-cores.

The skull morphology (long opisthocranium, weak slope of the cranial roof on the face, wide dorsal orbital rims, flat and wide fronto-nasal region, short and domed nasals, small occipital condyles, rectangular basioccipital, deep and large postcornual fossae, moderately long, weakly tilted, fairly curved backwards and moderately compressed mediolaterally horn-cores) are clearly different from those of G. pilgrimi from Axios valley (MNHN.F.Slq809) and Samos and very similar to those of G. capricornis from Pikermi (NHML M11440 , MNHN.F.PIK2001, MGPUA PA1355/91). Comparison of the horncore proportions between the Pikermi and the Maragheh samples does not show important size differences ( Fig. 2 ), whereas the horn-cores of G. deperdita from Mont Luberon ( France) appear more compressed mediolaterally (mean CI = 75% at the base, n = 31; mean CI = 74% at 7 cm above the base, n = 31).

The length of the upper molar row ranges from 33.7 mm (MAR1034) to 34.4 mm (MAR1028) ( Table 4). As in G. capricornis and G. deperdita and unlike G. pilgrimi the paracone rib of the Maragheh P4 is vertically placed and the parastyle of the upper molars is strong. Only a couple of lower toothrows can be securely attributed to this species ( Table 5). The lower premolar row represents 58.8-61.8% of the molars ( Fig. 4). The parastylid of the lower molars is well-developed, the p3 is simple with well-developed paraconid and the p4 has a strong paraconid and a subtriangular metaconid, which leaves the posterior valley open until an advanced stage of wear, in contrast to G. deperdita ( Heintz 1971) .

Figures

FIG. 3.— Gazella capricornis (Wagner,1848) cranium MMTT13/2583 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).