Systematics, Osteology, Sexual Dimorphism, Age Classes, and Population Dynamics of Teleoceras Fossiger from Jack Swayze Quarry, Clark County, Kansas, and Minium Quarry, Graham County, Kansas
Authors:   , Mullin Timothy 
Published: February 2023

The teleoceratines represent one of the most abundant and widespread Miocene rhinoceros groups. The Sternberg Museum of Natural History at Fort Hays State University houses a substantial collection of Teleoceras material from Jack Swayze Quarry (JSQ), Clark County, Kansas, and Minium Quarry (MQ), Graham County, Kansas. These samples were examined 10 identify bone types represented, and, where possible to identify specimens to species, determine their sex, and assign them to general age-classes. Likewise, inferences are made regarding the population structure or the samples, and photographs are provided highlighting osteological aspects. Detailed study of both of these samples is warranted in order to build upon previous investigations as well as to apply recently developed techniques. The general osteology or Teleoceras fossiger from JSQ and MQ is described. Podial material is figured and described to provide a useful reference to quickly identify these problematic elements. T. fossiger is recognized by its robust. proximodistally compressed limbs, metapodials, and podials: the extreme hypsodonty of the molars that lack a basal cingulum: the cross-sectional shape and size or the i2: and the shape and proponions of the skull. The overall morphology and craniodental and postcranial measurements suggest the presence or T. flossiger as the lone species of the genus in the samples from JSQ and MQ. Descriptive statistics and t-test results suggest that though the species or Teleoceras from JSQ and MQ are the same, the individuals present in MQ are, overall, significantly greater in breadth (girth) variables than the individuals in the sample from JSQ. Where possible, elements of Teleoceras fossiger are analyzed for the presence of sexual dimorphism. For JSQ, tibia length and proximal width, as well as femur plantar medial condyle width are interpreted as showing sexual dimorphism. For MQ, the distal width of the second metacarpal is the only sexually dimorphic character. The degree of sexual dimorphism in the samples of T fossiger from JSQ and MQ are considered tentative. Radial dimensions of the sample of T. fossigel from JSQ and MQ are less dimorphic than radial dimensions from the sample of T major from Ashfall Fossil Beds (Nebraska). The mandibles and maxillaries of Teleoceras fossiger from JSQ and MQ are assigned to wear stages and age classes. Results obtained from the application of recent methods are coincident, in selected cases, with previous ageing attempts for samples from JSQ and MQ, but vary in other cases. Some specimens from JSQ and MQ are assigned a wear stage and age class for the first time. Analyses of the degree of sexual dimorphism, as well as age class interpretations, yield inconclusive information regarding population dynamics for Teleoceras fossigel. Analogies are drawn for T. fossigel with extant hippopotami and rhinoceroses. However, comparison of these data to the samples from JSQ and MQ do not suggest whether T. fossiger was, in terms of population dynamics, more like extant hippopotami or rhinoceroses.