title: Oligocene sivaladapid primate from the Bugti Hills (Balochistan, Pakistan) bridges the gap between Eocene and Miocene adapiform communities in Southern Asia.
abstract: A new species of Guangxilemur (Sivaladapidae, Adapiformes) is described from the early Oligocene Chitarwata Formation (Bugti Member) of the Bugti Hills, Sulaiman geological Province, Balochistan, Pakistan. Guangxilemur singsilai n. sp. provides further diagnostic morphological characters from its newly described upper and lower dentitions, confirming its intermediate phylogenetic position between Eocene and Miocene Asian sivaladapid adapiforms. G. singsilai possesses moderately developed shearing and puncturing molar features and maintains lingual cusps on upper molars as in Eocene hoanghoniines; in contrast, it possesses a typical molariform P(4) as in Miocene sivaladapines. The important paleogeographic changes that have affected South Asia during the Tertiary (related to the collision between the Indian and Eurasian Plates) have played a critical role in reforming circulation and climatic differentiation. The presence in Pakistan of an unique and well-diversified Oligocene primate fauna, clearly demonstrates that South Asia maintained favourable environmental conditions during the middle Caenozoic global climatic deterioration that coincides with drastic changes in faunal structure on the whole Holarctic Province, including the extinction of adapiform primates.
authors.affiliation: Laboratoire de Paléontologie UMR 5554-CNRS, Institut des Sciences de l'Evolution, Cc064, Université Montpellier II, Place Eugène Bataillon, Montpellier, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Marivaux
authors.forename: Jean-Loup
authors.initials: JL
authors.lastname: Welcomme
authors.forename: Stéphane
authors.initials: S
authors.lastname: Ducrocq
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Jaeger
mesh_terms: D000818:Animals; D001208:Asia; D001641:Bicuspid / Q000033:anatomy & histology*; D005580:Fossils; D008963:Molar / Q000033:anatomy & histology*; D010154:Pakistan; D010161:Paleodontology; D010802:Phylogeny; D011323:Primates / Q000145:classification*