Skeletal adaptations in Bison latifrons to accommodate larger horn cores and vertebral sexual dimorphism in Bison bison

This study was conducted to determine the osteological adaptations used by B. latifrons to support the weight of their large head and horns. B. latifrons was assumed to essentially be a larger version of male B. bison with a somewhat larger skull and much larger horns. Thus, B. latifrons' cervical and anterior thoracic vertebral features were expected to exhibit size increases greater than the overall body size increase in order to support the head. However, the data demonstrated that the size increase of B. latifrons vertebral elements was less than that of the limb elements. Thus, male B. bison is not a simple analogue for B. latifrons . The analysis did not demonstrate any special adaptive features on B. latifrons cervical and anterior thoracic vertebrae.; The study did demonstrate that cervical and anterior thoracic vertebrae of male B. bison were almost uniformly larger than those of female B. bison. Male B. bison cervical and anterior thoracic vertebral features that have a 30% or greater increase of means as compared to equivalent female characters and have no overlap of range with the female B. bison are very probably adaptations to support the head. These criteria can be used for sexing male and female B. bison cervical and anterior thoracic vertebrae.