Biomechanics of Mammalian Feeding and Primate Evolution. Proceedings of a symposium. Research Triangle Park, North Carolina, USA. April 9-13, 1996.

Abstract

ABSTRACT Most of the papers included in this volume are derived frompresentations in a symposium on Mammalian Feeding at the 65th AnnualMeetings of the American Association of Physical Anthropologists in NorthCarolina in 1996. The aims of this symposium were to gather together thepreeminent researchers on mammalian mastication and document the stateof research in that field. The symposium emphasized in vivo studies ofmammalian feeding because of a paucity of recent reviews of this field, butincluded morphometric and modeling papers as well. Subsequently the pa-pers were revised, and were submitted in spring 1998 for publication, pend-ing the outcome of peer review. Am J Phys Anthropol 112:449–453, 2000. © 2000 Wiley-Liss, Inc. The study of feeding behavior in nonpri-mate mammals is relevant to the study ofprimate mastication in two ways. First,comparison of primates and nonprimatemammals can reveal ways in which pri-mates differ from other mammals, inform-ing hypotheses of the origin and radiation ofprimates. Second, study of a broad range ofmammals generates insights into the rulesand principles governing the evolution ofthe feeding apparatus in general, of whichthe primate system is an example.Many of the papers in this symposiumdealt with issues surrounding anthropoidorigins. The fossil record of the anthropoidstem group has greatly improved recentlywith the discovery of Early-Middle EoceneAsian taxa exhibiting a combination of pro-simian-like primitive and crown anthro-poid-like derived features of the jaws andteeth (Beard et al., 1996; Jaeger et al.,1999). Future work on these animals prom-ises to greatly enhance our understandingof the origins of the anthropoid feeding ap-paratus. Extant anthropoids that have beenstudied differ from strepsirrhine primatesin an array of features of the skull that aredemonstrably or have been hypothesized tobe part of the feeding apparatus, e.g., onto-genetically early fusion of the mandibularsymphysis, late activity in the balancing-side deep masseter muscle during the powerof mastication (Hylander et al., 1987; Hy-lander and Johnson, 1994), relatively greateractivity of balancing-side muscles (Hylander1977), greater isognathy (widths of upper andlower dental arcades are roughly similar; Ra-vosa and Hylander, 1994), relatively largerphase II occlusal facets, a longer power stroke(Hiiema¨e and Kay, 1973), and a postorbitalseptum (Cachel, 1979). Ravosa et al. (2000a,this volume) observe that crown anthropoidshave more isodontic molars (upper andlower molars roughly the same width) andmore vertically oriented superficial masse-ters than do strepsirrhines.Ross and Hylander (2000, this volume)evaluate hypotheses relating the function ofthe anterior temporalis muscles to the evo-lution of the postorbital septum (Ross,