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Kaye E Reed - One of the best experts on this subject based on the ideXlab platform.
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fossil suidae mammalia artiodactyla from lee adoyta ledi geraru lower awash valley ethiopia implications for Late Pliocene turnover and paleoecology
Palaeogeography Palaeoclimatology Palaeoecology, 2018Co-Authors: Ignacio A Lazagabaster, Joshua Robinson, John Rowan, Christopher J Campisano, Antoine Souron, Kaye E ReedAbstract:Abstract 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 2.95 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 (δ13C) data show a trend from C3-C4 mixed diets at Hadar to C4-dominated diets by ~2.82 Ma at Lee Adoyta, most likely C4 grasses. Suids decline in abundance almost linearly from ~3.76 to
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fossil giraffidae mammalia artiodactyla from lee adoyta ledi geraru and Late Pliocene dietary evolution in giraffids from the lower awash valley ethiopia
Journal of Mammalian Evolution, 2017Co-Authors: John Rowan, Joshua Robinson, Christopher J Campisano, Jonathan G Wynn, Ellis M Locke, Kaye E ReedAbstract:The giraffid fossils recovered from ~ 2.8–2.6 million year old (Ma) sediments from Lee Adoyta, Ledi-Geraru, Ethiopia, are described here. Sivatherium maurusium and Giraffa cf. G. gracilis are the two identified taxa, with the former being more abundant than the latter. We interpret this skew of relative abundance to be of paleoenvironmental significance, as Sivatherium is rare and Giraffa is common in the adjacent, but older sediments of the Hadar Formation at Hadar (~ 3.4 to 2.95 Ma), which was characterized by wooded and well-watered habitats through most of its sequence. Stable carbon isotope analyses show that Giraffa remained an obligate browser throughout the lower Awash Valley (LAV) sequence while Sivatherium underwent a dietary transition from a browser in the Hadar Formation to a grazer at Lee Adoyta. This dietary shift in Sivatherium reflects local environmental change through time in the LAV as open habitats spread during the Late Pliocene. A compilation of isotopic data from other sites in eastern Africa shows that the LAV dietary shift in Sivatherium occurred roughly one million years earlier than in the Turkana Basin, Kenya, reflecting a spatiotemporally staggered expansion of C4 vegetation across eastern Africa.
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Late Pliocene bovidae from ledi geraru lower awash valley ethiopia and their implications for afar paleoecology
Journal of Vertebrate Paleontology, 2017Co-Authors: Faysal Bibi, John Rowan, Kaye E ReedAbstract:ABSTRACTFossil 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 buffalo Ugandax coryndonae, the bongo-like Tragelaphus rastafari-nakuae lineage, an alcelaphin resembling Parmularius pachyceras, and a large impala. Differences from Hadar include the abundance of Kobus sigmoidalis, the absence of K. oricornus, and the presence of Tragelaphus gaudryi and probably also Menelikia lyrocera. The fossil bovids from Ledi-Geraru are mainly comparable to those known from contemporaneous assemblages in the Turkana Basin. Menelikia and T. gaudryi are characteristic of the Turkana Basin, and these are probably their first records from the Afar. A new species of Beatragus is 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...
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Late Pliocene environmental change during the transition from australopithecus to homo
Nature Ecology and Evolution, 2017Co-Authors: Joshua Robinson, John Rowan, Christopher J Campisano, Jonathan G Wynn, Kaye E ReedAbstract:It has long been hypothesized that the transition from Australopithecus to Homo in eastern Africa was linked to the spread of open and arid environments near the Plio−Pleistocene boundary, but data for the Latest Pliocene are scarce. Here we present new stable carbon isotope data from the Late Pliocene mammalian fauna from Ledi-Geraru, in the lower Awash Valley (LAV), Ethiopia, and mammalian community analyses from the LAV and Turkana Basin. These data, combined with pedogenic carbonate stable isotopes, indicate that the two regions were largely similar through the Plio−Pleistocene, but that important environmental differences existed during the emergence of Homo around 2.8 million years ago. The mid-Pliocene to Late Pliocene interval in the LAV was characterized by increasingly C4-dominated, arid and seasonal environments. The early Homo mandible LD 350-1 has a carbon isotope value similar to that of earlier Australopithecus from the LAV, possibly indicating that the emergence of Homo from Australopithecus did not involve a dietary shift. Late Pliocene LAV environments contrast with contemporaneous environments in the Turkana Basin, which were more woody and mesic. These findings have important implications for the environmental conditions surrounding the emergence of Homo, as well as recent hypotheses regarding Plio−Pleistocene environmental change in eastern Africa. Stable isotope and community faunal analysis of early hominid environments in the lower Awash Valley (Ethiopia) and Turkana Basin (Kenya/Ethiopia) reveal environmental change and divergence coincident with the emergence of the genus Homo (approx. 2.8 Ma).
John Rowan - One of the best experts on this subject based on the ideXlab platform.
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Late Pliocene Bovidae from Ledi-Geraru (Lower Awash Valley, Ethiopia) and their implications for Afar paleoecology
2019Co-Authors: Faysal Bibi, John Rowan, Kaye ReedAbstract: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 buffalo Ugandax coryndonae, the bongo-like Tragelaphus rastafari-nakuae lineage, an alcelaphin resembling Parmularius pachyceras, and a large impala. Differences from Hadar include the abundance of Kobus sigmoidalis, the absence of K. oricornus, and the presence of Tragelaphus gaudryi and probably also Menelikia lyrocera. The fossil bovids from Ledi-Geraru are mainly comparable to those known from contemporaneous assemblages in the Turkana Basin. Menelikia and T. gaudryi are characteristic of the Turkana Basin, and these are probably their first records from the Afar. A new species of Beatragus is also named. A well-preserved skull and skeleton of a fossil wildebeest from the Ogoyta sediments (
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fossil suidae mammalia artiodactyla from lee adoyta ledi geraru lower awash valley ethiopia implications for Late Pliocene turnover and paleoecology
Palaeogeography Palaeoclimatology Palaeoecology, 2018Co-Authors: Ignacio A Lazagabaster, Joshua Robinson, John Rowan, Christopher J Campisano, Antoine Souron, Kaye E ReedAbstract:Abstract 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 2.95 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 (δ13C) data show a trend from C3-C4 mixed diets at Hadar to C4-dominated diets by ~2.82 Ma at Lee Adoyta, most likely C4 grasses. Suids decline in abundance almost linearly from ~3.76 to
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fossil giraffidae mammalia artiodactyla from lee adoyta ledi geraru and Late Pliocene dietary evolution in giraffids from the lower awash valley ethiopia
Journal of Mammalian Evolution, 2017Co-Authors: John Rowan, Joshua Robinson, Christopher J Campisano, Jonathan G Wynn, Ellis M Locke, Kaye E ReedAbstract:The giraffid fossils recovered from ~ 2.8–2.6 million year old (Ma) sediments from Lee Adoyta, Ledi-Geraru, Ethiopia, are described here. Sivatherium maurusium and Giraffa cf. G. gracilis are the two identified taxa, with the former being more abundant than the latter. We interpret this skew of relative abundance to be of paleoenvironmental significance, as Sivatherium is rare and Giraffa is common in the adjacent, but older sediments of the Hadar Formation at Hadar (~ 3.4 to 2.95 Ma), which was characterized by wooded and well-watered habitats through most of its sequence. Stable carbon isotope analyses show that Giraffa remained an obligate browser throughout the lower Awash Valley (LAV) sequence while Sivatherium underwent a dietary transition from a browser in the Hadar Formation to a grazer at Lee Adoyta. This dietary shift in Sivatherium reflects local environmental change through time in the LAV as open habitats spread during the Late Pliocene. A compilation of isotopic data from other sites in eastern Africa shows that the LAV dietary shift in Sivatherium occurred roughly one million years earlier than in the Turkana Basin, Kenya, reflecting a spatiotemporally staggered expansion of C4 vegetation across eastern Africa.
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Late Pliocene bovidae from ledi geraru lower awash valley ethiopia and their implications for afar paleoecology
Journal of Vertebrate Paleontology, 2017Co-Authors: Faysal Bibi, John Rowan, Kaye E ReedAbstract:ABSTRACTFossil 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 buffalo Ugandax coryndonae, the bongo-like Tragelaphus rastafari-nakuae lineage, an alcelaphin resembling Parmularius pachyceras, and a large impala. Differences from Hadar include the abundance of Kobus sigmoidalis, the absence of K. oricornus, and the presence of Tragelaphus gaudryi and probably also Menelikia lyrocera. The fossil bovids from Ledi-Geraru are mainly comparable to those known from contemporaneous assemblages in the Turkana Basin. Menelikia and T. gaudryi are characteristic of the Turkana Basin, and these are probably their first records from the Afar. A new species of Beatragus is 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...
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Late Pliocene environmental change during the transition from australopithecus to homo
Nature Ecology and Evolution, 2017Co-Authors: Joshua Robinson, John Rowan, Christopher J Campisano, Jonathan G Wynn, Kaye E ReedAbstract:It has long been hypothesized that the transition from Australopithecus to Homo in eastern Africa was linked to the spread of open and arid environments near the Plio−Pleistocene boundary, but data for the Latest Pliocene are scarce. Here we present new stable carbon isotope data from the Late Pliocene mammalian fauna from Ledi-Geraru, in the lower Awash Valley (LAV), Ethiopia, and mammalian community analyses from the LAV and Turkana Basin. These data, combined with pedogenic carbonate stable isotopes, indicate that the two regions were largely similar through the Plio−Pleistocene, but that important environmental differences existed during the emergence of Homo around 2.8 million years ago. The mid-Pliocene to Late Pliocene interval in the LAV was characterized by increasingly C4-dominated, arid and seasonal environments. The early Homo mandible LD 350-1 has a carbon isotope value similar to that of earlier Australopithecus from the LAV, possibly indicating that the emergence of Homo from Australopithecus did not involve a dietary shift. Late Pliocene LAV environments contrast with contemporaneous environments in the Turkana Basin, which were more woody and mesic. These findings have important implications for the environmental conditions surrounding the emergence of Homo, as well as recent hypotheses regarding Plio−Pleistocene environmental change in eastern Africa. Stable isotope and community faunal analysis of early hominid environments in the lower Awash Valley (Ethiopia) and Turkana Basin (Kenya/Ethiopia) reveal environmental change and divergence coincident with the emergence of the genus Homo (approx. 2.8 Ma).
Youbin Sun - One of the best experts on this subject based on the ideXlab platform.
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iron fertilisation and biogeochemical cycles in the sub arctic northwest pacific during the Late Pliocene intensification of northern hemisphere glaciation
Earth and Planetary Science Letters, 2011Co-Authors: Ian Bailey, Youbin Sun, Qingsong Liu, George E A Swann, Zhaoxia Jiang, Xiang Zhao, Andrew P RobertsAbstract:Abstract Increases in the low-field mass-specific magnetic susceptibility (χ), dropstones and the terrigenous sediment component from Ocean Drilling Program (ODP) Site 882 (~ 45°N) have been interpreted to indicate a major onset of ice-rafting to the sub-Arctic northwest Pacific Ocean during marine isotope stage (MIS) G6 (from ~ 2.75 Ma). In contrast, studies of the terrigenous content of sediments cored downwind of ODP Site 882 indicate that dust and disseminated volcanic ash deposition in the sub-Arctic Pacific increased markedly during MIS G6. To investigate the relative contribution of dust, volcanic ash and ice rafting to the Pliocene χ increase, we present new high-resolution environmental magnetic and ice-rafted debris records from ODP Sites 882 and 885. Our results demonstrate that the χ increase at both sites across MIS G6 is predominantly controlled by a previously overlooked mixture of aeolian dust and volcanic ash. Our findings call into question the reliability of χ as a proxy for ice-rafting to the North Pacific. They also highlight a previously undocumented link between iron fertilisation and biogeochemical cycling in the North Pacific at a key stage during intensification of Late Pliocene northern hemisphere glaciation.
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Late Pliocene pleistocene changes in mass accumulation rates of eolian deposits on the central chinese loess pLateau
Journal of Geophysical Research, 2005Co-Authors: Youbin SunAbstract:[1] Late Pliocene-Pleistocene changes in the mass accumulation rates (MARs) of eolian deposits on the central Chinese Loess PLateau (CLP) are reconstructed from measured bulk sediment densities combined with sedimentation rates calcuLated for two loess/red clay sequences. The reconstructed MARs demonstrate that over the past 3600 kyr, distinct aridity-humidity fluctuations occurred over glacial-interglacial timescales, and these were superimposed on a gradual long-term drying trend. Comparisons of the CLP MAR record with the MAR and δ18O records for marine sediments suggest that the development of Northern Hemisphere ice sheets since the Late Pliocene has played a part in increasing the aridity of central Asia. In addition, the phased uplift of the Himalaya-Tibetan PLateau evidently had a profound influence on the aridity of central Asia; this was mediated by variations in the East Asian monsoonal circulation. Correlations among dust records from ice cores, marine sediments, and terrestrial loess over the last several glacial cycles provide compelling evidence that glacial periods are characterized by higher and more variable dust fluxes than interglacial intervals. Synchronous changes in the MAR, grain size, and δ18O records reveal dynamic linkages between Asian interior aridity, paleowind intensity, and ice volume after the onset of major Northern Hemisphere glaciations.
Joshua Robinson - One of the best experts on this subject based on the ideXlab platform.
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fossil suidae mammalia artiodactyla from lee adoyta ledi geraru lower awash valley ethiopia implications for Late Pliocene turnover and paleoecology
Palaeogeography Palaeoclimatology Palaeoecology, 2018Co-Authors: Ignacio A Lazagabaster, Joshua Robinson, John Rowan, Christopher J Campisano, Antoine Souron, Kaye E ReedAbstract:Abstract 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 2.95 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 (δ13C) data show a trend from C3-C4 mixed diets at Hadar to C4-dominated diets by ~2.82 Ma at Lee Adoyta, most likely C4 grasses. Suids decline in abundance almost linearly from ~3.76 to
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fossil giraffidae mammalia artiodactyla from lee adoyta ledi geraru and Late Pliocene dietary evolution in giraffids from the lower awash valley ethiopia
Journal of Mammalian Evolution, 2017Co-Authors: John Rowan, Joshua Robinson, Christopher J Campisano, Jonathan G Wynn, Ellis M Locke, Kaye E ReedAbstract:The giraffid fossils recovered from ~ 2.8–2.6 million year old (Ma) sediments from Lee Adoyta, Ledi-Geraru, Ethiopia, are described here. Sivatherium maurusium and Giraffa cf. G. gracilis are the two identified taxa, with the former being more abundant than the latter. We interpret this skew of relative abundance to be of paleoenvironmental significance, as Sivatherium is rare and Giraffa is common in the adjacent, but older sediments of the Hadar Formation at Hadar (~ 3.4 to 2.95 Ma), which was characterized by wooded and well-watered habitats through most of its sequence. Stable carbon isotope analyses show that Giraffa remained an obligate browser throughout the lower Awash Valley (LAV) sequence while Sivatherium underwent a dietary transition from a browser in the Hadar Formation to a grazer at Lee Adoyta. This dietary shift in Sivatherium reflects local environmental change through time in the LAV as open habitats spread during the Late Pliocene. A compilation of isotopic data from other sites in eastern Africa shows that the LAV dietary shift in Sivatherium occurred roughly one million years earlier than in the Turkana Basin, Kenya, reflecting a spatiotemporally staggered expansion of C4 vegetation across eastern Africa.
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Late Pliocene environmental change during the transition from australopithecus to homo
Nature Ecology and Evolution, 2017Co-Authors: Joshua Robinson, John Rowan, Christopher J Campisano, Jonathan G Wynn, Kaye E ReedAbstract:It has long been hypothesized that the transition from Australopithecus to Homo in eastern Africa was linked to the spread of open and arid environments near the Plio−Pleistocene boundary, but data for the Latest Pliocene are scarce. Here we present new stable carbon isotope data from the Late Pliocene mammalian fauna from Ledi-Geraru, in the lower Awash Valley (LAV), Ethiopia, and mammalian community analyses from the LAV and Turkana Basin. These data, combined with pedogenic carbonate stable isotopes, indicate that the two regions were largely similar through the Plio−Pleistocene, but that important environmental differences existed during the emergence of Homo around 2.8 million years ago. The mid-Pliocene to Late Pliocene interval in the LAV was characterized by increasingly C4-dominated, arid and seasonal environments. The early Homo mandible LD 350-1 has a carbon isotope value similar to that of earlier Australopithecus from the LAV, possibly indicating that the emergence of Homo from Australopithecus did not involve a dietary shift. Late Pliocene LAV environments contrast with contemporaneous environments in the Turkana Basin, which were more woody and mesic. These findings have important implications for the environmental conditions surrounding the emergence of Homo, as well as recent hypotheses regarding Plio−Pleistocene environmental change in eastern Africa. Stable isotope and community faunal analysis of early hominid environments in the lower Awash Valley (Ethiopia) and Turkana Basin (Kenya/Ethiopia) reveal environmental change and divergence coincident with the emergence of the genus Homo (approx. 2.8 Ma).
Christopher J Campisano - One of the best experts on this subject based on the ideXlab platform.
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fossil suidae mammalia artiodactyla from lee adoyta ledi geraru lower awash valley ethiopia implications for Late Pliocene turnover and paleoecology
Palaeogeography Palaeoclimatology Palaeoecology, 2018Co-Authors: Ignacio A Lazagabaster, Joshua Robinson, John Rowan, Christopher J Campisano, Antoine Souron, Kaye E ReedAbstract:Abstract 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 2.95 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 (δ13C) data show a trend from C3-C4 mixed diets at Hadar to C4-dominated diets by ~2.82 Ma at Lee Adoyta, most likely C4 grasses. Suids decline in abundance almost linearly from ~3.76 to
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fossil giraffidae mammalia artiodactyla from lee adoyta ledi geraru and Late Pliocene dietary evolution in giraffids from the lower awash valley ethiopia
Journal of Mammalian Evolution, 2017Co-Authors: John Rowan, Joshua Robinson, Christopher J Campisano, Jonathan G Wynn, Ellis M Locke, Kaye E ReedAbstract:The giraffid fossils recovered from ~ 2.8–2.6 million year old (Ma) sediments from Lee Adoyta, Ledi-Geraru, Ethiopia, are described here. Sivatherium maurusium and Giraffa cf. G. gracilis are the two identified taxa, with the former being more abundant than the latter. We interpret this skew of relative abundance to be of paleoenvironmental significance, as Sivatherium is rare and Giraffa is common in the adjacent, but older sediments of the Hadar Formation at Hadar (~ 3.4 to 2.95 Ma), which was characterized by wooded and well-watered habitats through most of its sequence. Stable carbon isotope analyses show that Giraffa remained an obligate browser throughout the lower Awash Valley (LAV) sequence while Sivatherium underwent a dietary transition from a browser in the Hadar Formation to a grazer at Lee Adoyta. This dietary shift in Sivatherium reflects local environmental change through time in the LAV as open habitats spread during the Late Pliocene. A compilation of isotopic data from other sites in eastern Africa shows that the LAV dietary shift in Sivatherium occurred roughly one million years earlier than in the Turkana Basin, Kenya, reflecting a spatiotemporally staggered expansion of C4 vegetation across eastern Africa.
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Late Pliocene environmental change during the transition from australopithecus to homo
Nature Ecology and Evolution, 2017Co-Authors: Joshua Robinson, John Rowan, Christopher J Campisano, Jonathan G Wynn, Kaye E ReedAbstract:It has long been hypothesized that the transition from Australopithecus to Homo in eastern Africa was linked to the spread of open and arid environments near the Plio−Pleistocene boundary, but data for the Latest Pliocene are scarce. Here we present new stable carbon isotope data from the Late Pliocene mammalian fauna from Ledi-Geraru, in the lower Awash Valley (LAV), Ethiopia, and mammalian community analyses from the LAV and Turkana Basin. These data, combined with pedogenic carbonate stable isotopes, indicate that the two regions were largely similar through the Plio−Pleistocene, but that important environmental differences existed during the emergence of Homo around 2.8 million years ago. The mid-Pliocene to Late Pliocene interval in the LAV was characterized by increasingly C4-dominated, arid and seasonal environments. The early Homo mandible LD 350-1 has a carbon isotope value similar to that of earlier Australopithecus from the LAV, possibly indicating that the emergence of Homo from Australopithecus did not involve a dietary shift. Late Pliocene LAV environments contrast with contemporaneous environments in the Turkana Basin, which were more woody and mesic. These findings have important implications for the environmental conditions surrounding the emergence of Homo, as well as recent hypotheses regarding Plio−Pleistocene environmental change in eastern Africa. Stable isotope and community faunal analysis of early hominid environments in the lower Awash Valley (Ethiopia) and Turkana Basin (Kenya/Ethiopia) reveal environmental change and divergence coincident with the emergence of the genus Homo (approx. 2.8 Ma).
