COMPARATIVE DENTAL OCCLUSAL MORPHOLOGY, FACET DEVELOPMENT, AND MICROWEAR IN 2 SYMPATRIC SPECIES OF LISTRIODON (MAMMALIA, SUIDAE) FROM THE MIDDLE MIOCENE OF WESTERN ANATOLIA (TURKEY)

The occurrence of two species of the suid Listriodon at the middle Mio cene locality Pasalar, western Anatolia, offers a rare possibility to compare dental wear and microwear in sympatric, closely related specie s. We studied ail the worn tooth surfaces available in a sample of the lophodont Listriodon cf. L. splendens and the sublophodont L. aff. L. latidens from Pasalar, using simple methods to describe and quantify various aspects of wear. Major differences between dental surfaces and Various sets of occlusal facets can be shown within and between the s pecies. The differences within species among ''major,'' ''minor,'' and ''phase II'' facets are pronounced, more so than the difference betwe en buccal and lingual facet groupings. The difference between species is most marked for the phase II facets, which also have the largest we ar features. The between-species difference (but not the between-facet group difference) is much stronger for moderately worn teeth than for little-worn or much-worn teeth. The more developed lophodonty, earlie r major facet development, and smaller maximum pit sizes in L. cf. L. splendens, compared to L. aff. L. latidens, all are consistent with th e interpretation that L. cf. L. splendens was a more specialized foliv ore than L. aff. L. latidens and other less lophodont listriodonts.