Stratigraphic context and taxonomic assessment of the large cercopithecoid (Primates, Mammalia) from the late Early Pleistocene palaeoanthropological site of Buia (Eritrea)

Abstract

IntroductionThe Buia-Dandero area (100 km south of Massawa, northernDanakil Depression, Eritrea; Fig. 1A) is well known for the 1-million-year-old Homo cranium from Buia (Abbate et al., 1998;Macchiarelli et al., 2004; Bondioli et al., 2006). The Early-to-Middle Pleistocene stratigraphic series of the Dandero basin,located near the Buia village, presents about 1 km of continentaldeposits. Since its discovery in 1994, this area has been the subjectof research by an international team coordinated by the EarthSciences Department of the University of Florence and the EritreaNational Museum. The investigated area yielded hominin remains(Abbate et al., 1998, 2004a; Rook et al., 2002), abundant fossilvertebrates (Ferretti et al., 2003; Delfino et al., 2004; Martinez-Navarro et al., 2004, 2010), and a rich archaeological record ofMode 1 (Oldowan) and Mode 2 (Acheulean) tool industries in a lateEarly Pleistocene chronological framework (Abbate et al., 2004a).The age of the Homo-bearing sediments (Alat Formation) of theBuia sedimentary succession, established by different investigativeapproaches, falls within the Jaramillo Subchron (C1r.1n), close to1.0Ma(Albianelli and Napoleone, 2004; Bigazzi et al., 2004).In addition to the hominin remains, non-human primates aresolely represented in the Buia faunal assemblage (Alat Formation)by a large cercopithecoid cranial fragment, tentatively listed in theBuia mammal fauna (Martinez-Navarro et al., 2004)asTher-opithecus cf. Theropithecus oswaldi. The genus Theropithecus is verycommon in the Plio-Pleistocene of Africa, occurring at sites inNorth, East and South Africa, within a time span ranging from3.4Mato0.5Ma(Delsonetal.,1993).Weprovidehereadescriptionof the specimen (UA-463), which is housed in the Paleontologicalcollections of the National Museum of Eritrea (Asmara).The mammalian assemblage from BuiaAbbateetal.(1998)publishedapreliminaryvertebratefaunallistfrom Buia. Successive field collections and taxonomic descriptionsallowed updating the Buia vertebrate faunal assemblage, whichrepresentsatypicaleasternAfricanlateEarlyPleistocenefauna.Buiais characterised by the occurrence of evolved last-representativeforms of Elephas recki, Hippopotamus gorgops, Kolpochoerus old-uvaiensis, Kolpochoerus majus, Metridiochoerus aff. M. modestus andBos buiaensis, associated with taxa that persist in the present day,such as Ceratotherium simum, Equus cf. E. grevyi, Tragelaphus cf.Theropithecus spekei, and Kobus cf. K. ellipsiprymnus. The geologicaland sedimentological framework, as well as paleomagnetism andfissiontrackdating(Abbateetal.,2004a;Ghinassietal.,2009)areingood agreement with the mammal biochronology data, attesting toa latest Early Pleistocene age (Martinez-Navarro et al., 2004, 2010).Thisvertebrateassemblageispredominantlycomposedoftaxawithstrong water dependence like hippos, waterbuck, sitatunga, Kolpo-choerus, crocodiles, paleomedusid chelonians and African rock