First discovery of the spiral-horned antelope Antilospira(Bovidae,Artiodactyla)from the Linxia Basin,Gansu,ChinaOA

Antilospira is a small to medium-sized antelope with heteronymously spiraled horn cores.It was widely distributed in northern China from the Late Pliocene to the Early Pleistocene.It is a typical fossil bovid with important implications for biostratigraphy and antilopin evolution in China.Antilospira robusta is a species with highly fragmentary materials and has previously only been briefly discussed.Here we report on a new frontal with horn cores from the Early Pleistocene Wucheng Loess in Nalesi Township,Dongxiang Autonomous County,Linxia Basin,Gansu Province.This new material features heteronymously spiraled horn cores,deep longitudinal grooves,a sharp anterior carena on the horn core,and a large body size,which are characteristics similar to those of A.robusta.However,the horn base of the new material is more compressed than all the previously discovered spiral-horned antelopes,so we attributed it to Antilospira cf.A.robusta.This is the first time Antilospira has been found in northwestern China,and this discovery provides more morphological data for the classification of this group.CT scans of the horn core reveal the well-remodeled horn core trabeculae in Antilospira,which is different from what is observed in Spirocerus.The frontal sinuses are moderately developed in the Linxia specimen,extending backwards to the orbit but not to the horn base.The virtual reconstruction of the endocranial cast indicated that Antilospira has bending and narrow frontal lobes,wide temporal lobes,and relatively complex sulci on the cerebral hemisphere,which differ from extant Antilopini bovids in China.