1132


Journal of Paleontology


Piedad-Santa Ana, and 16 for Viko Vijin (see Supplemental dataset 1). Although it was originally suggested that the mini- mum number of observations to obtain a robust mesowear sig- nal should be 10 (Fortelius and Solounias, 2000; Kaiser et al., 2000), later studies suggested that smaller sample sizes are sufficient to offer insights into paleodiet and paleoecology (Bernor et al., 2014). Since then, many studies have offered paleodietary and paleoecological inferences with small sample sizes, ranging from nine to three, and even one (Danowitz et al., 2016). For the scoring of mesowear variables (Fig. 3), the labial


portion of the ectoloph cusps of the paracone and metacone were observed and categorized by their relief (high or low) and their shape (sharp, rounded, or blunt) (Fortelius and Solounias, 2000). To control interobserver error when scoring relief, we employed the methodological proposal of Merceron et al. (2007) in which the relief state (high or low) was obtained by dividing the distance that connects the highest point of the evaluated cusp and the lowest point of the intercuspidal area (Fig. 3.1, x) by the cusp height (Fig. 3.1, y); when the value was greater than two, we considered it as a low cusp. We employed the software ImageJ 1.50i (Ferreira and Rasband, 2012) for these measurements. Also, we scored cusp shape according to the degree of facet development: (1) when no facets were distinguishable, we considered the cusp as blunt; (2) when there was no distinguishable junction between facets, we considered the cusp as rounded; and (3)


when this junction was distinguishable, we considered the cusp as sharp (Fortelius and Solounias, 2000; Kaiser et al., 2000; Merceron et al., 2007). We also evaluated the lingual facets (mesial and distal) of


the paracone and its junction (Fig. 3.2), categorizing the facets within the following stages: (1) flat surface with no gouges, (2) nearly flat surface with some gouges, (3) rounded surface with abundant gouges, or (4) smooth rounded surface with no gouges and poorly defined edges. The j-junction was categorized in one of the following stages: (1) well-defined, sharp edge; (2) poorly defined edge with some gouges; (3) rounded edge, poorly defined, smooth, but still-differentiated edge; or (4) undiffer- entiated mesial and distal cusps, and j-junction lost (Solounias et al., 2014; Danowitz et al., 2016). We observed the analyzed molars with a stereoscopic


microscope to discard those with taphonomical alterations such as mechanical fractures (Fortelius and Solounias, 2000) or abrasion caused by sand (Blondel et al., 2010). To minimize subjectivity when recording mesowear variables, we compared our scorings with the original diagrams and photographs of Fortelius and Solounias (2000) and Danowitz et al. (2016), assuring that we obtained similar results to those of experienced observers, because mesowear is less prone to observer variation than other methods such as dental microwear (Loffredo and DeSantis, 2014). To identify the mesowear pattern associated with a particular dietary category (browser, mixed feeder, strict grazer,


Figure 3. Mesowear variables: (1) categorization of traditional and extended mesowear variables: shape and relief. Relief is considered high when x/y ≤ 2, or low when x/y>2; (2) mesowear III variables: j-junction (where mesial and distal enamel bands meet) and mesial/distal enamel band score system.


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