Hominoid phalanges from the middle Miocene site of Paşalar, Turkey

Eleven proximal and ten intermediate partial or complete hominoid phalanges have been recovered from the middle Miocene site of Paşalar in Turkey. Based on species representation at Paşalar, it is likely that most or all of the phalanges belong to Griphopithecus alpani rather than Kenyapithecus kizili, but both species may be represented. All of the complete or nearly complete phalanges appear to be manual, so comparisons to extant and other fossil primate species were limited to manual phalanges. Comparisons were made to extant hominoid and cercopithecoid primate genera expressing a variety of positional repertoires and varying degrees of arboreality and terrestriality. The comparisons consisted of a series of bivariate indices derived from previous publications on Miocene catarrhine phalangeal morphology. The proximal phalanges have dorsally expanded proximal articular surfaces, which is characteristic of cercopithecoids and most other Miocene hominoids, and indicates that the predominant positional behaviors involved pronograde quadrupedalism. Among the extant primates, many of the proximal and intermediate phalangeal indices clearly distinguish more habitually terrestrial taxa from those that are predominantly arboreal, and especially from taxa that commonly engage in suspensory activities. For nearly every index, the values of the Paşalar phalanges occupy an intermediate position-most similar to values for Pan and, to a lesser extent, Macaca-indicating a generalized morphology and probably the use of both arboreal and terrestrial substrates. At least some terrestrial activity is also compatible with reconstructions of the Paşalar habitat. Most proximal and intermediate phalanges of other middle and late Miocene hominoids have similar index values to those of the Paşalar specimens, revealing broadly similar manual phalangeal morphology among many Miocene hominoids.