Gavkosh - a new locality yielding large mammal fossils in the Bakhtiari Formation in Lorestan Province, Iran

Abstract

A new vertebrate fossil assemblage was discovered during road construction works near Gavkosh, Lorestan Province, Iran. The fossils come from a succession of conglomerates, sands and marls of fluvial origin. At least three high concentration fossiliferous horizons occur within a stratigraphic thickness of about 2 m and a distance of some12 m. The fossils are well-preserved, though many are broken due to the circumstances of the discovery. The new fossil locality is from the Bakhtiari Formation, which is the last synorogenetic deposit of the Zagros foreland basin and has a stratigraphic thickness of up to 3000 m and extends for over 1000 km along the SW of the Zagros Mountains. Because of its relevance for the orogenetic history of these mountains, the age of this formation is under discussion with proposed ages varying between latest Oligocene to Pleistocene. The preliminary identifications of the fossils lead to the recognition of seven to eight species of Carnivora, Perissodactyla and Artiodactyla: Felidae indet., Hipparion spp. A & B (Equidae), Giraffidae indet. and Gazella sp., Boselaphini indet, Bovidae indet. spp. 1 & 2 (Bovidae). The composition of the assemblage recalls that of the classic fauna from Marageh (Iran) and the fauna from Injana (Iraq), both of middle Late Miocene age, but it cannot be excluded that it is of a different age between about 11 to 2.6 Ma. The fauna from Gavkosh is in a biogeographically interesting position between the ¿Pikermian¿ faunas (such as Marageh) and the Siwalik faunas of the Indian Subcontinent.