Fossils from Mille-Logya, Afar, Ethiopia, elucidate the link between Pliocene environmental changes and Homo origins

Several hypotheses posit a link between the origin of Homo and climatic and environmental shifts between 3 and 2.5 Ma. Here we report on new results that shed light on the interplay between tectonics, basin migration and faunal change on the one hand and the fate of Australopithecus afarensis and the evolution of Homo on the other. Fieldwork at the new Mille-Logya site in the Afar, Ethiopia, dated to between 2.914 and 2.443 Ma, provides geological evidence for the northeast migration of the Hadar Basin, extending the record of this lacustrine basin to Mille-Logya. We have identified three new fossiliferous units, suggesting in situ faunal change within this interval. While the fauna in the older unit is comparable to that at Hadar and Dikika, the younger units contain species that indicate more open conditions along with remains of Homo. This suggests that Homo either emerged from Australopithecus during this interval or dispersed into the region as part of a fauna adapted to more open habitats.info:eu-repo/semantics/publishedVersio

Crossing new frontiers: extending tephrochronology as a global geoscientific research tool

Tephrochronology is a unique stratigraphic tool for linking, dating, and synchronising geological, palaeoenvironmental, or archaeological sequences and events (Lowe, 2011; Alloway et al., 2013). It relies on the identification and tracing of tephra or cryptotephra horizons spatially between various depositional sequences. These horizons can provide stratigraphic event layers (tephrostratigraphy) and, when dated, isochronous age markers — since most tephra are deposited on a scale of days to weeks — that can be transferred from site to site (tephrochronology) (Lane et al., 2017b). The correlation of horizons between different sequences is reliant on matching the physical characteristics, mineralogical assemblages, and geochemical compositions of minerals and/or glass shards in tephra deposits using a range of analytical methods and visual and statistical approaches (e.g. Lowe et al., 2017). Correlating tephra deposits back to their volcanic source allows tephrochronological studies to provide information on the eruption frequency and geochemical evolution of volcanic regions and individual volcanoes

Mammal community structure analysis

Peer reviewe

Evidence for Stone Tool-Assisted Consumption of Animal Tissues Before 3.39 Million Years Ago at Dikika, Ethiopia

The oldest direct evidence of stone tool manufacture comes from Gona (Ethiopia) and dates to between 2.6 and 2.5 million years (Myr) ago1. At the nearby Bouri site several cut-marked bones also show stone tool use approximately 2.5 Myr ago2. Here we report stone-tool-inflicted marks on bones found during recent survey work in Dikika, Ethiopia, a research area close to Gona and Bouri. On the basis of low-power microscopic and environmental scanning electron microscope observations, these bones show unambiguous stone-tool cut marks for flesh removal and percussion marks for marrow access. The bones derive from the Sidi Hakoma Member of the Hadar Formation. Established 40Ar–39Ar dates on the tuffs that bracket this member constrain the finds to between 3.42 and 3.24 Myr ago, and stratigraphic scaling between these units and other geological evidence indicate that they are older than 3.39 Myr ago. Our discovery extends by approximately 800,000 years the antiquity of stone tools and of stone-tool-assisted consumption of ungulates by hominins; furthermore, this behaviour can now be attributed to Australopithecus afarensis