Journal of Paleontology, 92(6), 2018, p. 1130–1139 Copyright © 2018, The Paleontological Society 0022-3360/15/0088-0906 doi: 10.1017/jpa.2018.19


A combined mesowear analysis of Mexican Bison antiquus shows a generalist diet with geographical variation


Roberto Díaz-Sibaja,1 Eduardo Jiménez-Hidalgo,2 Javier Ponce-Saavedra,3 and María Luisa García-Zepeda4


1Programa Institucional de Doctorado en Ciencias Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán de


Ocampo, México ⟨roberto.diaz.sibaja@gmail.com⟩ 2Laboratorio de Paleobiología, Instituto de Recursos, Campus Puerto Escondido, Universidad del Mar, Oaxaca, México ⟨eduardojh@zicatela.


umar.mx⟩ 3Laboratorio de Entomología, ‘Biologo Sócrates Cisneros Paz,’ Facultad de Biología, Universidad Michoacana de San Nicolás de Hidalgo,


Morelia, Michoacán de Ocampo, México ⟨ponce.javier0691@gmail.com⟩ 4Laboratorio de Paleontología, Facultad de Biología, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán de Ocampo, México ⟨gzepeda@zeus.umich.mx⟩


Abstract.—Bison antiquus Leidy, 1852 was one of the largest and most widely distributed megafaunal species during the Late Pleistocene in North America, giving rise to the modern plains bison in the middle Holocene. Despite the importance of the ancient bison, little is known about its feeding ecology. We employed a combination of extended mesowear, and mesowear III to infer the dietary preference and habitat use of three Mexican samples of B. antiquus. These included two northern samples—La Piedad-Santa Ana and La Cinta-Portalitos—from the Transmexican Volcanic Belt morphotectonic Province, as well as one southern sample—Viko Vijin—from the Sierra Madre del Sur morphotectonic province. We found that the northern Mexican samples were primarily nonstrict grazers, whereas the southern sample displays a pattern consistent with mixed feeding habits. This suggests variability among the diets of the bison from these samples, caused by different paleoenvironments. This evidence complements the paleoenvironmental reconstructions in the studied localities; for the northern samples, open prairies composed of patches of woodland or shrubland and, for the southern locality, a flu- vial floodplain with short-lived vegetation. In both scenarios, grasses (Poaceae) were nondominant. The dietary habits of our samples of ancient bison in Mexico are the southernmost dietary inference for the species in North America and expand our knowledge of the dietary habits of B. antiquus during the Late Pleistocene.


Introduction


Dental mesowear is a useful tool to infer the diet of extinct herbivores. It was originally developed for herbivorous mam- mals with lophodont teeth and labiolingual mandibular excur- sion, and it was based on the analysis of the relief (high or low) and shape (sharp, rounded, or blunt) of the ectoloph’s second upper molar cusps (Fortelius and Solounias, 2000). Later, the original method was extended to include analysis of the upper third molar in ruminants (Franz-Odendaal and Kaiser, 2003). Also, three univariate scales of dental wear have been developed to facilitate the comparison between mesowear patterns; one ranging from 0 to 3 is used for upper dentition (Rivals et al., 2007b), the second from 0 to 4 is employed for upper postcanine dentition (Kaiser, 2011; Kaiser et al., 2013), and the other from 1 to 5 is used for both upper and lower teeth (Fraser et al., 2014). Recently, mesowear III was developed to analyze the lingual enamel band of the paracone and metacone; this method has a scoring system that considers four wear stages (1 to 4) of the mesial and distal enamel bands, and the shape of its junction (also 1 to 4), where each stage is associated with the attrition signal, linked to a particular dietary guild (Solounias et al.,


2014). The original mesowear score, its modifications, and the mesowear III method can be used together to better predict ruminant diet than any single variable (Danowitz et al., 2016). Mesowear is considered one of the main dietary approaches


to infer diet (Fortelius and Solounias, 2000; Hoffman, 2006; Semprebon and Rivals, 2007; Rivals et al., 2009a, b; Blondel et al., 2010), along with other approaches, such as stable carbon isotope analysis and dental microwear. In ruminants, mesowear provides additional information, such as geographical (Rivals et al., 2007b) and temporal variation of diet (Rivals and Semprebon, 2006; Fraser and Theodor, 2013). One of the most conspicuous ruminants in the North


American Pleistocene was the bison (Bison spp.); it was the largest, most numerous, and the most widely distributed rumi- nant (McDonald, 1981; Shapiro et al., 2004). Bison ranged from Baillie Island in the Yukon, Canada (Harrington, 1990) to Matagalpa, Nicaragua (Howell and MacDonald, 1969). Across this wide geographical range, bison mesowear studies are scarce, and are focused on topics such as diet quality in Bison bison (Linnaeus, 1758) (Berini, 2010), ontogenetic diet varia- tion in B. priscus (Bojanus, 1827) (Rivals et al., 2007a), and geographical diet variation in some species of the genus (Rivals


1130


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91  |  Page 92  |  Page 93  |  Page 94  |  Page 95  |  Page 96  |  Page 97  |  Page 98  |  Page 99  |  Page 100  |  Page 101  |  Page 102  |  Page 103  |  Page 104  |  Page 105  |  Page 106  |  Page 107  |  Page 108  |  Page 109  |  Page 110  |  Page 111  |  Page 112  |  Page 113  |  Page 114  |  Page 115  |  Page 116  |  Page 117  |  Page 118  |  Page 119  |  Page 120  |  Page 121  |  Page 122  |  Page 123  |  Page 124  |  Page 125  |  Page 126  |  Page 127  |  Page 128  |  Page 129  |  Page 130  |  Page 131  |  Page 132  |  Page 133  |  Page 134  |  Page 135  |  Page 136  |  Page 137  |  Page 138  |  Page 139  |  Page 140  |  Page 141  |  Page 142  |  Page 143  |  Page 144  |  Page 145  |  Page 146  |  Page 147  |  Page 148  |  Page 149  |  Page 150  |  Page 151  |  Page 152  |  Page 153  |  Page 154  |  Page 155  |  Page 156  |  Page 157  |  Page 158  |  Page 159  |  Page 160  |  Page 161  |  Page 162  |  Page 163  |  Page 164  |  Page 165  |  Page 166  |  Page 167  |  Page 168  |  Page 169  |  Page 170  |  Page 171  |  Page 172  |  Page 173  |  Page 174  |  Page 175  |  Page 176  |  Page 177  |  Page 178  |  Page 179  |  Page 180  |  Page 181  |  Page 182  |  Page 183  |  Page 184  |  Page 185  |  Page 186  |  Page 187  |  Page 188  |  Page 189  |  Page 190