02253nas a2200265   4500008004100000022001400041245009000055210006900145260001600214300001000230490000700240520144200247653001701689653001101706653001701717653001501734653003101749653005401780100001901834700001801853700002001871700002301891700001801914856005501932       2016                        eng d  a1064-755400aAre Hypsodonty and Occlusal Enamel Complexity Evolutionarily Correlated in Ungulates?0 aAre Hypsodonty and Occlusal Enamel Complexity Evolutionarily Cor  cJan-05-2016  a43-470 v233 a<p>The spread of grasslands and cooling climate in the Miocene contributed to an increasingly abrasive diet for ungulates. This increase in abrasiveness is proposed to select for both hypsodonty and increasing complexity of occlusal enamel bands. If these traits evolved in response to strong selection to resist tooth wear while feeding in grassland habitats, we might expect them to have evolved in a correlated fashion. If, on the other hand, there was a developmental or physiological constraint, or if selection was not strong on total enamel production, we would expect species to have evolved one or the other of these traits at a time, producing an uncorrelated, or even inversely correlated, pattern of trait evolution. To test these hypotheses, we examined the Occlusal Enamel Index (OEI) and Hypsodonty Index (HI) of 773 ungulate teeth. We tested the dependence of OEI on HI for the orders Artiodactyla and Perissodactyla using phylogenetic generalized least squares regression (PGLS). The two traits are not significantly correlated in the PGLS, for Artiodactyla and Perissodactyla. Despite their physical proximity, close functional utility, and conventional correlation, our results reject the hypothesis that HI and OEI are evolutionarily linked in these lineages, suggesting that selection to resist tooth wear was not so strong as to drive the overall evolutionary trajectory of both these traits at the same time.</p>
10aArtiodactyla10aEquini10aHipparionini10ahypsodonty10aOcclusal enamel complexity10aPhylogenetic generalized least squares regression1 aFamoso, N., A.1 aDavis, E., B.1 aFeranec, R., S.1 aHopkins, S., S. B.1 aPrice, S., A.  uhttp://link.springer.com/10.1007/s10914-015-9296-7