Frank Sénégas

Early Modern Humans and Morphological Variation in Southeast Asia: Fossil Evidence from Tam Pa Ling, Laos

Little is known about the timing of modern human emergence and occupation in Eastern Eurasia. However a rapid migration out of Africa into Southeast Asia by at least 60 ka is supported by archaeological, paleogenetic and paleoanthropological data. Recent discoveries in Laos, a modern human cranium (TPL1) from Tam Pa Ling‘s cave, provided the first evidence for the presence of early modern humans in mainland Southeast Asia by 63-46 ka. In the current study, a complete human mandible representing a second individual, TPL 2, is described using discrete traits and geometric morphometrics with an emphasis on determining its population affinity. The TPL2 mandible has a chin and other discrete traits consistent with early modern humans, but it retains a robust lateral corpus and internal corporal morphology typical of archaic humans across the Old World. The mosaic morphology of TPL2 and the fully modern human morphology of TPL1 suggest that a large range of morphological variation was present in early modern human populations residing in the eastern Eurasia by MIS 3.

Early Modern Humans from Tam Pà Ling, Laos: Fossil Review and Perspectives

Despite the importance of its geographical position for early modern human migration through Australasia, the Indochinese Peninsula has produced relatively few fossils or well-documented archaeological sites, resulting in a poor chronology for early occupation. Tam Pà Ling (TPL), a cave in northern Laos, is one of the rare sites yielding fossils contemporaneous with the earliest migrants into Australasia within a securely established chronology. From its discovery in 2008 until the most recently filed season in 2016, TPL has provided evidence of a modern human presence in the region by marine isotope stages 4 and 3. A partial cranium (TPL1), two mandibles (TPL2, TPL3), and assorted postcranial fragments (TPL4, TPL5) represent the earliest well-dated, anatomically modern humans in the Indochinese Peninsula and introduce new migration routes into the area. The sedimentary context of TPL is described and refined elsewhere, resulting in an approximate age of 44–63 ka for the TPL1 and TPL2 fossils and a maximum depositional age of 70 ka for the lowest layer containing the TPL3 mandible. This is 20 ka older than the depositional ages for the TPL1 and TPL2 fossils and establishes a new upper limit for sedimentary deposition at the site and for the associated fossil evidence. In this study, we review previously presented material (TPL1–TPL3), present unpublished postcranial material (TPL4 and TPL5), and provide dental metric analysis of the TPL1–TPL3 specimens.

Les recherches franco-malgaches sur les lémuriens subfossiles du Nord-Ouest de Madagascar

RésuméDepuis plus d’un siècle, les recherches à Madagascar ont permis de découvrir 17 espèces de lémuriens éteints, tous de grande taille. Ils pratiquaient des locomotions qui ne se rencontrent plus aujourd’hui chez les lémuriens actuels. Certains présentaient des convergences morphologiques avec des Catarrhiniens ou d’autres groupes de Mammifères. Peu de choses étaient connues pour le Nord-Ouest du pays. 13 ans d’activités sur le terrain d’une équipe franco-malgache ont permis de combler le vide qui existait pour cette région. Une nouvelle espèce de lémurien subfossile pratiquant des déplacements dans les arbres avec la tête en bas comme les paresseux actuels d’Amérique du Sud, a été découverte. La biodiversité des lémuriens connue entre 26 000 ans et il y a cinq siècles était encore plus importante qu’aujourd’hui. Un effort particulier a été fait pour permettre des reconstitutions paléoenvironnementales. La méthodologie mise en place a ainsi permis la découverte de deux espèces de rongeurs éteints. La découverte de traces anthropiques très anciennes montre que l’homme a coexisté pendant longtemps avec les subfossiles. S’il a eu une action sur l’extinction de ces faunes, elle n’a pas été immédiate.AbstractMore than a century of research in Madagascar has yielded 17 species of extinct lemurs, all of large size and all with patterns of locomotor behaviour that are not found in extant lemurs. Some morphological convergence has been recognized with Catarrhini and other groups of mammals, but very little research had been conducted in north-western Madagascar. Thirteen years of fieldwork by a French-Malagasy team has now produced a large body of information on subfossils in this area. A new species of subfossil lemur was discovered with similar locomotor behaviour than the extant South-American sloth. The known biodiversity of lemurs from 26 000 to 500 years ago was even greater than it is today. Particular efforts were made regarding palaeoenvironmental reconstruction. Our methodology brought the discovery of two species of extinct rodent and of very ancient anthropic traces indicating that humans coexisted with subfossil species for longer than was previously thought. While humans may have been ultimately responsible for their extinction, the impact of their presence was not immediate.