A NEW SPECIMEN OF ANKARAPITHECUS-METEAI FROM THE SINAP FORMATION OF CENTRAL ANATOLIA

HOMINOID fossils from the Middle and Late Miocene are exceedingly rare , yet such material is necessary for determining hominoid phylogeny, W e report here the discovery of a fossil hominoid partial skull from th e Upper Miocene Sinap Formation(1,2) of central Turkey that is the mos t complete known from the period of 18 to 3 Myr. Our fieldwork places the hominoid locality within a precisely dated geochronological and bi ostratigraphical framework(3) that permits detailed comparisons with o ther fossil hominoids. Earlier discoveries of more fragmentary remains of Ankarapithecus meteai suggested affinities with the Asian hominoid s Sivapithecus and Pongo(4). This new and nearly complete specimen rev eals a combination of facial, mandibular, and dental features includin g a relatively narrow interorbital region, extensive frontal and maxil lary sinuses, moderately developed supraorbital tori, square orbits, r obust mandibular corpus, and incisor heteromorphy that is not matched in any extant or fossil hominoid. This configuration of features seems to support its placement as a stem member of the great ape and human clade.