Urmiatherium polaki Rodler, 1889

Kostopoulos, Dimitris S., 2014, Taxonomic re-assessment and phylogenetic relationships of Miocene homonymously spiral-horned antelopes, Acta Palaeontologica Polonica 59 (1), pp. 9-29 : 19

Urmiatherium polaki Rodler, 1889

Holotype: Partial skull ( Rodler 1889: pls. 1–4; cast NHMUK M4114); according to Rodler (1889) the holotype skull was part of a private collection by J.E. Polak. Unfortunately, I was unable to locate it in any of the mentioned institutions.

Type locality: Maragheh, Iran (unknown level).

Type horizon: Turolian, Late Miocene.

Emended diagnosis (modified from Jafarzadeh et al. 2012).— Medium to large−sized species of Urmiatherium with an almost flat occipito−parietal angle; parietals almost absent from skull roof; face deep and long, with a moderately broad rostrum; nasals relatively long and not in contact with the premaxillae; lacrimal fossae moderately deep; ethmoidal fissure absent; orbits relatively small and round, and located posterior to the level of M3; horncores short and distinctly grooved, showing weak homonymous torsion, fused at the base, and with a slightly posteriorly curved distal portion; lower molars with strong parastylids and weak goat folds, but without basal pillars; upper molars with strong paracone ribs and central islets.

Remarks.—Until recently, this species was known only from its opisthocranium ( Rodler 1889; Mequenem 1925), but a newly discovered specimen from the type area provides details of most of its cranial morphology ( Jafarzadeh et al. 2012). Some metapodials from Maragheh provide additional information about the postcranial anatomy of this species, as well as its ecological adaptations ( Kostopoulos and Bernor 2011).

Geographic and stratigraphic range.— Urmiatherium polaki has so far only been reporeted from the middle and upper intervals of the Maragheh sequence, Iran, with its oldest possible record dated to 7.7– 8.6 Ma ( Jafarzadeh et al. 2012).