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Camels are exceptionally rare in the Plio-Pleistocene fossil record of Africa, hindering attempts to understand the evolution of this family on the continent. Here we describe recently collected camel specimens from the Shungura Formation, Lower Omo Valley, Ethiopia, and attribute these remains to Camelus grattardi. The new specimens date to the late Pliocene (~3 to 2.6 Ma) and consist of three upper molars, one upper premolar, and two proximal metatarsals. The dental specimens confirm this species' small P4 relative to its molars, a trait that differs significantly from all extant and fossil Old World camels. The metatarsals indicate that C. grattardi was similar in size to the living Bactrian camel, C. bactrianus. Phylogenetically, we find no suitable ancestor, sister, or descendant of the eastern African fossil camel, which suggests greater lineage diversity in Plio-Pleistocene Camelus than previously recognised. Microwear analyses suggest that C. grattardi was likely a mixed-feeder preferring browse, which is consistent with carbon isotopes of enamel from the Turkana Basin. A review of the fossil record of African camels suggests no clear paleoenvironmental association, as fossil camels occur in a range of environments from dry savannas with no permanent water bodies to closed woodlands along the paleo-Omo River. [ABSTRACT FROM AUTHOR]

The Kibish Formation of southern Ethiopia has yielded the earliest fossils of Homo sapiens , ca. 196 ka, and has thus figured prominently in discussions of the origins of modern humans. Here we describe the fossil Bovidae from the Kibish Formation, a record that spans the late Middle Pleistocene to the early to mid-Holocene, and reconstruct aspects of their dietary ecology using mesowear analyses. All of the Kibish bovids represent extant taxa with the exception of the extinct blesbok-like alcelaphin Damaliscus hypsodon ; extinct arid-adapted forms Syncerus antiquus and Megalotragus , common in other Late Quaternary sites, are notably absent. Mesowear of the Kibish bovids suggests that the Late Quaternary specimens were characterized by diets with considerably more abrasion-dominated wear relative to their extant conspecifics. Finally, the Kibish record provides supporting evidence for recent phylogeographic hypotheses by demonstrating significant range expansions of Aepyceros melampus , Connochaetes taurinus , Hippotragus equinus , and, to a lesser extent, Kobus kob in the late Middle Pleistocene through the early to mid-Holocene coincident with humid phases that punctuated dry spells of the Late Quaternary. [ABSTRACT FROM AUTHOR]

Fossil bovids are described from the late Pliocene site of Ledi-Geraru, mainly from the Gurumaha and Lee Adoyta sedimentary packages (2.8–2.6 Ma). Finds include taxa already known from the slightly older Hadar Formation, such as the buffaloUgandax coryndonae, the bongo-likeTragelaphus rastafari-nakuaelineage, an alcelaphin resemblingParmularius pachyceras, and a large impala. Differences from Hadar include the abundance ofKobus sigmoidalis, the absence ofK. oricornus, and the presence ofTragelaphus gaudryiand probably alsoMenelikia lyrocera. The fossil bovids from Ledi-Geraru are mainly comparable to those known from contemporaneous assemblages in the Turkana Basin.MenelikiaandT. gaudryiare characteristic of the Turkana Basin, and these are probably their first records from the Afar. A new species ofBeatragusis also named. A well-preserved skull and skeleton of a fossil wildebeest from the Ogoyta sediments (<2.4 Ma) bears a mosaic of advanced and conserved traits that illuminate the evolution of theConnochaetesclade prior to the divergence of its two extant species. Taxonomic abundance, as well as functional analyses of postcranial elements, indicates that the ancient landscape at Ledi-Geraru was primarily made up of open habitats such as seasonal grasslands, with minor components of woodlands and wetlands. This contrasts with most localities from the Hadar Formation, which record more covered habitats. Comparisons with older Afar faunas indicate that environmental changes to drier and more open habitats were part of a long-term trend that goes back to at least 4 Ma, if not earlier. http://zoobank.org/urn:lsid:zoobank.org:pub:0A4AF06A-9918-4AFE-B3D1-633DE036EDCB SUPPLEMENTAL DATA—Supplemental materials are available for this article for free atwww.tandfonline.com/UJVP Citation for this article: Bibi, F., J. Rowan, and K. Reed. 2017. Late Pliocene Bovidae from Ledi-Geraru (Lower Awash Valley, Ethiopia) and their implications for Afar paleoecology. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1337639. [ABSTRACT FROM AUTHOR]

The fossiliferous late Pliocene deposits of the Lee Adoyta sub-basin, lower Awash Valley (LAV), Ethiopia, sample a poorly-known time interval in this region (~2.82 to <2.5 Ma). Recent fieldwork in Lee Adoyta by the Ledi-Geraru Research Project has produced a rich mammalian fauna, including the earliest specimen of the genus Homo . Here, we describe the fossil Suidae (pigs) and provide taxonomic and paleoecological comparisons with other sites in the LAV (e.g., Hadar, Woranso-Mille). The Lee Adoyta suid fossils document the presence of at least three species, including Notochoerus cf. No. capensis , Kolpochoerus phillipi , and Metridiochoerus andrewsi , all of which are absent from the older deposits in the LAV (>2.95 Ma). However, two of these species ( No . cf. No. capensis and K. phillipi ) have likely ancestors known from the Hadar Formation ( No. euilus and K. afarensis ), implying a continuity of suid lineages through the Pliocene LAV. A compilation of stable carbon isotope (δ 13 C) data show a trend from C 3 -C 4 mixed diets at Hadar to C 4 -dominated diets by ~2.82 Ma at Lee Adoyta, most likely C 4 grasses. Suids decline in abundance almost linearly from ~3.76 to <2.5 Ma in the LAV, which we propose is related to the expansion of open, grassier habitats during this time. [ABSTRACT FROM AUTHOR]

The Shungura Formation (Lower Omo Valley, Ethiopia) constitutes one of the most complete stratigraphic and paleontological records for the Plio-Pleistocene of eastern Africa and has yielded a large collection of fossil bovids, in which the most abundant tribe is Reduncini (waterbucks, kobs, and relatives). We used a multi-proxy approach to precisely reconstruct the diet and habitat preferences of Shungura reduncins to better understand of the environmental conditions that prevailed during the Plio-Pleistocene in the Lower Omo Valley. We compared the dental microwear texture analyses and the dental mesowear analyses for fossil samples dating to between 3 Ma and 1.7 Ma. We show that reduncins from the Shungura Formation had a diet dominated by browse at around 2.8 Ma, had diets ranging from browsing to mixed feeding from 2.8 Ma to 2.3 Ma, and consumed far more graze around 2.3 Ma and 1.8 Ma. Our study highlights the benefits of a multi-proxy approach to dietary reconstruction and how each dietary proxy can be leveraged to offer a slightly different, complementary perspectives on the ecology of fossil organisms. • Dental mesowear and microwear texture analyses were applied to Plio-Pleistocene reduncins. • They had diets ranging from browsing to mixed feeding from 2.8 Ma to 2.3 Ma. • They were more engaged in grazing around 2.3 Ma and 1.8 Ma. • Multi-proxy approaches are needed to precisely determine the diets of fossil organisms. [ABSTRACT FROM AUTHOR]

The Early Pleistocene was a critical time period in the evolution of eastern African mammal faunas, but fossil assemblages sampling this interval are poorly known from Ethiopia's Afar Depression. Field work by the Hadar Research Project in the Busidima Formation exposures (~2.7-0.8 Ma) of Hadar in the lower Awash Valley, resulted in the recovery of an early Homo maxilla (A.L. 666-1) with associated stone tools and fauna from the Maka'amitalu basin in the 1990s. These assemblages are dated to ~2.35 Ma by the Bouroukie Tuff 3 (BKT-3). Continued work by the Hadar Research Project over the last two decades has greatly expanded the faunal collection. Here, we provide a comprehensive account of the Maka'amitalu large mammals (Artiodactyla, Carnivora, Perissodactyla, Primates, and Proboscidea) and discuss their paleoecological and biochronological significance. The size of the Maka'amitalu assemblage is small compared to those from the Hadar Formation (3.45-2.95 Ma) and Ledi-Geraru (2.8-2.6 Ma) but includes at least 20 taxa. Bovids, suids, and Theropithecus are common in terms of both species richness and abundance, whereas carnivorans, equids, and megaherbivores are rare. While the taxonomic composition of the Maka'amitalu fauna indicates significant species turnover from the Hadar Formation and Ledi-Geraru deposits, turnover seems to have occurred at a constant rate through time as taxonomic dissimilarity between adjacent fossil assemblages is strongly predicted by their age difference. A similar pattern characterizes functional ecological turnover, with only subtle changes in dietary proportions, body size proportions, and bovid abundances across the composite lower Awash sequence. Biochronological comparisons with other sites in eastern Africa suggest that the taxa recovered from the Maka'amitalu are broadly consistent with the reported age of the BKT-3 tuff. Considering the age of BKT-3 and biochronology, a range of 2.4-1.9 Ma is most likely for the faunal assemblage., Competing Interests: The authors declare that they have no competing interests., (© 2022 Rowan et al.)

Sedimentary basins in eastern Africa preserve a record of continental rifting and contain important fossil assemblages for interpreting hominin evolution. However, the record of hominin evolution between 3 and 2.5 million years ago (Ma) is poorly documented in surface outcrops, particularly in Afar, Ethiopia. Here we present the discovery of a 2.84- to 2.58-million-year-old fossil and hominin-bearing sediments in the Ledi-Geraru research area of Afar, Ethiopia, that have produced the earliest record of the genus Homo. Vertebrate fossils record a faunal turnover indicative of more open and probably arid habitats than those reconstructed earlier in this region, which is in broad agreement with hypotheses addressing the role of environmental forcing in hominin evolution at this time. Geological analyses constrain depositional and structural models of Afar and date the LD 350-1 Homo mandible to 2.80 to 2.75 Ma., (Copyright © 2015, American Association for the Advancement of Science.)

Our understanding of the origin of the genus Homo has been hampered by a limited fossil record in eastern Africa between 2.0 and 3.0 million years ago (Ma). Here we report the discovery of a partial hominin mandible with teeth from the Ledi-Geraru research area, Afar Regional State, Ethiopia, that establishes the presence of Homo at 2.80 to 2.75 Ma. This specimen combines primitive traits seen in early Australopithecus with derived morphology observed in later Homo, confirming that dentognathic departures from the australopith pattern occurred early in the Homo lineage. The Ledi-Geraru discovery has implications for hypotheses about the timing and place of origin of the genus Homo., (Copyright © 2015, American Association for the Advancement of Science.)