A New Look at an Old Face: The Hoà Binh Late Pleistocene Pongo Skull and Other Faciodental Fragments From Breccia Caves in Vietnam—A Morphometric Assessment With Taxonomic Implications

Objectives: The taxonomic status of the Middle and Late Pleistocene pongines from northern Vietnam remains obscure. Two current schemes dominate. The first has multiple species of Pongo and Langsonia occupying the region during the late Middle and Late Pleistocene. The second has just two species, with the large species P. weidenreichi from the Early to Late Pleistocene of China evolving into the smaller P. devosi from the Middle/Late Pleistocene transition. Here, we generate several multivariate analyses against the available faciodental specimens from present-day northern Vietnam to test these two schemes and assess the morphotypes of these specimens.
Materials and Methods: Discriminant factor and principal components analyses were both used against 51 extant hominids (Pongo, Gorilla and the two species of Pan) with 105 faciodental variables to examine the near-complete subfossil Hoà Binh skull. Additional fossils from the Late Pleistocene of this region were also analyzed. All specimens used were original.
Results: We conclude that there was a diverse range of Pongo species in the region of northern Vietnam. We recognize two large and two small species during the Late Pleistocene. One of the larger species occupied this region toward the end of the Late Pleistocene, thus refuting the chronospecies hypothesis.
Discussion: This study suggests the extinction of mainland Pongo species is associated with the rapid decline in habitat during the Late Pleistocene. Orangutan populations further south in Sumatra and Borneo (still then part of Mainland Asia) survived in safe havens of relic rainforests.