Lithostratigraphic context for Kln-1993.05-SNJ, a fossil colobine maxilla from Jokotingkir, Sangiran dome

Jablonski and Tyler (1999) announced a Mew subspecies of colobine monkey ba sed on a fossil partial maxilla from the Sangiran dome. The specimen is eas ily assigned to a living leaf monkey species-most extant Southeast Asian ca tarrhines differ only subspecifically from their Middle Pleistocene earlies t local fossil ancestors. Yet Jablonski and Tyler (1999) reported an improb able provenance for the specimen; a mass-flow volcanic breccia generally co nsidered late Pliocene in age. We show that the Lower Lahar was laid down a midst a range of paludal habitats and that its deposition predates the appe arance of all-but-now extinct, water-tolerant mammals on emergent Java. No other catarrhine fossil has been ascribed to the Lower Lahar, not even homi nins, which are the most gregarious members of the group. More probable pro venance lies in the upper Sangiran or the lower Bapang formations. Either a lternative would associate the specimen with other catarrhine fossils in mo re tenable Pleistocene environments. We also unravel errors and inconsisten cies in the contextual report and in the discussion of dome geochronology. The various radiometric, paleomagnetic, and paleontologic studies cited sho w a discordance of about 300 Ka (thousand years) across the lithostratigrap hic sequence. Plio-Pleistocene biogeographic hypotheses for Java must work with short and long chronologies.