Late Miocene large mammals from Ivand (Northwestern Iran) Author Ataabadi, Majid Mirzaie Author Mohammadalizadeh, Jafar Author Zhang, Zhaoqun Author Watabe, Mahito Author Kaakinen, Anu Author Fortelius, Mikael text Geodiversitas 2011 2011-12-31 33 4 709 728 http://dx.doi.org/10.5252/g2011n4a7 journal article 7713 10.5252/g2011n4a7 03becb1a-f3c9-410a-997c-37416648bc7d 1638-9395 4597129 Oioceros atropatenes Rodler & Weithofer, 1890 ( Fig. 7E, F ) LOCALITY. — Quarry 1, Ivand district, north of Tabriz, Iran . MATERIAL EXAMINED. — Left horn-core ( HMNH-IV 200; Fig. 7E, F ), right mandible with p4-m3 ( HMNH-IV 67; Table 3 ), right mandible with broken m2 and complete m3 ( HMNH-IV 69; Table 3 ). DESCRIPTION The horn-core specimen is partly broken at the base and the tip. The antero-posterior diameter cannot be measured precisely due to the basal missing part on both the anterior and posterior sides. However, we estimate that it exceeds 17 mm . The medio- A M1 M2 M3 M4 M6 M7 M14 M15 M23 M25 M30 M31 M32 M33 lateral diameter is 17.4 mm . The DAP and DT at 5 cm above the base are 12.7 mm and 10.9 mm , respectively. The total preserved length is 75 mm from the pedicle. By the preserved part of the orbit and remnant of the frontal, the horn-core is located above the posterior part of the orbit, tilted slightly backwards with a weak curvature. The horn-core is slender with a roughly oval cross section. The antero-posterior and transverse diameters diminish slowly from the base upwards. There are two weak keels, one starting from the antero-lateral side, and the other from the postero-lateral side. These two keels enclose a slightly convex outer surface and a more rounded inner surface. The keels spiral clock- wise roughly one gyre from the base to the tip by estimation. There is also a postcornual fossa. FIG. 4. — Logarithmic ratio diagrams comparing the skull of Hipparion sp. Large (HMNH-IV1) from the Ivand locality to: A , H. brachy­ pus Hensel, 1862, H. cf. proboscideum , and H. giganteum Gromova, 1952 from localities in the eastern Mediterranean and northern Black Sea regions; and B , “ H. î gettyi Bernor, 1985 , “ H. î aff. moldavicum ( H. moldavicum Gromova, 1952 sensu Watabe & Nakaya 1991b ), H. campbelli Bernor, 1985 and H. prostylum Gervais, 1849 from Maragheh, NW Iran. Standard, H. primigenium Meyer, 1833 , Höwenegg ( Bernor et al. 1997 ). p4 is long and narrow. The paraconid is not separated from the parastylid. The anterior valley is wide. The metaconid is situated posterior to the protoconid. The entoconid is close to the entostylid. A wide and shallow valley separates the protoconid from the hypoconid.m1 is well worn. The parastylid is developed, and well separated from the metaconid. There is no goat fold, thus rendering the anterior border much narrower. The lingual wall is flat with weak metastylids. The entostylid is larger. There is a large basal pillar between the protoconid and the metaconid. m2 is very similar in morphology to m1, except for its larger, more convex lingual wall, and lower basal pillar. The parastylid on m3 is more pronounced and well separated from the metaconid. The basal pillar is small and low. The hypoconulid is large and postero-labially offset. COMPARISON Based on the small size, insertion above the posterior part of orbit, the clockwise torsion on the left horn-core from the base, and two keels, the horn-core IV200 from Ivand locality can readily be assigned to the genus Oioceros ( type species Antelope rothii Wagner, 1857 from Pikermi, Greece ) ( Gaillard 1902 ). Since then, numerous species were included or assigned to this genus. De Mecquenem (1924) recognized three species from Maragheh: O . rothii (Wagner, 1857) , O . atropatenes and O . boulei Mecquenem, 1924 . Heintz (1963) synonymized O . boulei with O . atropatenes based on his detailed description and comparison. Roussiakis (2003) recently described in detail an almost complete skull with mandibles of Oioceros rothii from Pikermi and reviewed the generic status. Besides the type species, he listed only Oioceros atropatenes in the genus. The present specimen is smaller and less laterally compressed than Oioceros rothii from Pikermi. The main keel is much weaker and the upper part of the horn-core diverges less. The size falls into the variation of Oioceros atropatenes from Maragheh, Iran ( Heintz 1963 ). The morphology of the horn-core is also consistent with those from Maragheh. Hence, the horn-core specimen can be assigned to Oioceros atropatenes .