Node Calibrated. Last common ancestor of great apes, including human, chimp, gorilla, and orang-utan.

Fossil Taxon and Specimen. Sivapithecus indicus (e.g., Geological Survey of Pakistan, Islamabad, partial maxilla GSP Y-16075; Kappleman et al., 1991) from the Miocene Chinji Formation of Pakistan.

Phylogenetic Justification. Sivapithecus is identified by phylogenetic analysis as a member of total-group Ponginae, a stem gibbon, and so nested within crown Hominidae (Ward and Kimbel, 1983; Seiffert, 2006).

Minimum Age. 11.6 Ma

Soft Maximum Age. 33.9 Ma

Age Justification. The Chinji Formation of Pakistan corresponds to magnetic polarity chron 5Ar, estimated to be ca. 12 Ma before present (Kappelman et al., 1991). This correlates to the Serravallian stage, the top of which is at 11.6 Ma, our minimum estimate for the divergence of the orang-utan from other great apes.

As a soft maximum we suggest the first diverse occurrence of anthropoids from the earliest Oligocene of the Fayûm, Egypt. These primates

comprise a diverse radiation just on the Oligocene side of the Eocene-Oligocene boundary at 33.9 Ma (Seiffert, 2006; Gradstein et al., 2012), and lack derived features of the extant great ape lineages.

Discussion. While there are numerous taxa of fossil hominoids from Africa and Eurasia, few can be unambiguously attributed to an extant ape lineage besides Homo and Pongo. Numerous fossils associated with the Pongo lineage are known from Pleistocene sites in east Asia; another fossil orang-utan relative, Gigantopithecus, is known from the late Miocene and Pliocene (Fleagle, 1999). Of crown hominoid lineages, Sivapithecus is the oldest (Andrews and Cronin, 1982; Pilbeam, 1986).