Morphological peculiarity of the fossil bison (Bison priscus) from Yakutia

Abstract

The steppe bison (Bison priscus) is one of the most widespread and numerous representatives of the mammoth fauna. However, the features of the extinction of steppe bison at the end of the Pleistocene and their replacement by modern forms of the American bison (Bison bison) and European bison (Bison bonasus) have not yet been fully studied. Thus, complete skulls of fossil steppe bison are of great interest for studies on taxonomy and kinship relations in the genus Bison. This article presents the results of a study of the finely preserved skull of a fossil bison found in the Verkhoyansk district (Yakutia). This skull was compared by its morphological and osteometric features with other bison skulls, which were found at different times and locations in Upper Pleistocene deposits, as well as with the skulls of modern American bison Bison bison from the collection of the Zoological Museum of the Lomonosov Moscow State University. Standard morphometric indicators of bison skulls and horns were obtained using the Skinner and Kaisen measurement methods. Analysis showed that skulls of Bison priscus from Late Pleistocene sediments of Yakutia, according to most parameters, correspond to the maximum size of modern American bison Bison bison or even larger than the latter. The horns of bison from the Late Pleistocene are 1.5–2 times larger in size than the horns of modern bison and are comparable to those of the Middle Pleistocene long-horned bison B. p. crassicornis Richardson (=longicornis). The disproportion in the size of the skull and horns of the Late Pleistocene bison is due to their habitat in the open landscapes of the Arctic steppe. The morphological uniqueness of the steppe bison of the Late Pleistocene in Yakutia has prospects for further research, because it deserves to be identified as an independent taxon (subspecies), which is relevant for regional paleontology and stratigraphy.