Evidence for geographic variation in the diets of late Pleistocene and early HoloceneBisonin North America, and differences from the diets of recentBison

Abstract

During the late Pleistocene and early Holocene, Bison was widely dispersed across North America and occupied most regions not covered by ice sheets. A dietary study on Bison paleopopulations from Alaska, New Mexico, Florida, and Texas was performed using two methods that relate dental wear patterns to diet, mesowear analysis and microwear analysis. These data were compared to a mixed sample of extant Bison from the North American central plains, extant wood Bison from Alberta (Canada) and a variety of other modern ungulates. Mesowear relates macroscopic molar facet shape to levels of dietary abrasion. The mesowear signature observed on fossil Bison differs significantly from the hyper-abrasive grazing diet of extant Bison. Tooth microwear examines wear on the surface of enamel at a microscopic scale. The microwear signal of fossil samples resembles to modern Bison, but the fossil samples show a greater diversity of features, suggesting that fossil Bison populations regularly consumed food items that are texturally inconsistent with the short-grass diet typical of modern plains Bison. Mesowear and microwear signals of fossil Bison samples most closely resemble a variety of typical mixed feeding ungulates, all with diets that are substantially less abrasive than what is typical for modern plains Bison. Furthermore, statistical tests suggest significant differences between the microwear signatures of the fossil samples, thus revealing geographic variability in Pleistocene Bison diets. This study reveals that fossils are of value in developing an understanding of the dietary breadth and ecological versatility of species that, in recent times, are rare, endangered, and occupy only a small remnant of their former ranges.

Patterns of diet and body mass of large ungulates from the Pleistocene of Western Europe, and their relation to vegetation

“…Highly abrasive diet typical for grazers causes low and blunt wear relief on the teeth. This method has been successfully applied to fossil ungulate teeth (e.g., Kaiser, 2004;Mihl-4 bachler and Solounias, 2006;Rivals et al, 2007;Croft and Weinstein, 2008;DeMiguel et al, 2008;Kahlke and Kaiser, 2011;Mihlbachler et al, 2011) and is grounded in studies of modern ungulates of known diet (e.g., Fortelius and Solounias, 2000;Clauss et al, 2007). Morphological adaptations improving wear resistance of herbivorous mammal teeth, such as increased molar crown height (hypsodonty), reflect the conditions under which they evolved and have been shown to be adaptive both to environmental factors (such as precipitation and erosion rates, which regulate the accumulation of mineral particles on plant material), as well as to dietary factors (abrasive food items, mainly grass).…”

“…Note that this method of calculating mesowear as a univariate value is similar in principle to those used by Rivals et al (2007) and , but instead of using numeric values from 0 to 3 to reflect the combined cusp height and shape of each individual and then averaging across the sample, we obtain sample averages of cusp height and shape separately and then combine to calculate the final mesowear value. This was done because it more closely follows the original methodology, as introduced by Fortelius and Solounias (2000), allowing for all combinations of cusp shape and relief.…”

Seasonality and intra-site variation of Neanderthal occupations in the Middle Palaeolithic locality of Payre (Ardèche, France) using dental wear analyses

“…A combination of sharp cusps and high relief was assigned a score of 0; a combination of rounded cusps and high relief was assigned a score of 1; a combination of rounded cusps and low relief was assigned a score of 2; a combination of blunt cusps and low relief was assigned a score of 3. An overall mesowear score for each sample was then calculated by averaging individual mesowear scores (see an example of application in Rivals et al, 2007b andRivals, 2007).…”

Controlled feeding trials with ungulates: a new application of in vivo dental molding to assess the abrasive factors of microwear

“…principal components analysis, discriminant function analysis) to partition species among dietary guilds that are defined a priori based on observations of extant species (e.g. Merceron et al, 2006;Rivals et al, 2007;Theodor, 2011, 2013).…”