Geochronology

Deino, Alan L.

doi:10.1002/9781118332344.ch13

Cited by 11 publications

(15 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Weak stratification and irregular redox stains suggest initial soil development occurred during playa lake regression (18,22), around 1.848 Ma (ref. 23 and SI Discussion). To date, craniodental remains from at least three hominin individuals (18)(19)(20), including preadolescent early Homo and Paranthropus boisei, were recovered from FLK Zinj.…”

Section: Significancementioning

confidence: 99%

“…The behavioral implications of local conditions require understanding of regional climate and biogeography (3)(4)(5)7), because hominin species likely had home ranges much larger than the extent of excavated sites at FLK Zinj. Lake sediments at Olduvai Gorge include numerous stacked tuffs with precise radiometric age constraints (23). These tephrostratigraphic correlations (21) tie the FLK Zinj landscape horizon to published records of plant biomarkers in lake sediments that record climate cycles and catchment-scale variations in ecology.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Dietary options and behavior suggested by plant biomarker evidence in an early human habitat

Magill

Ashley

Domı́nguez-Rodrigo

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The availability of plants and freshwater shapes the diets and social behavior of chimpanzees, our closest living relative. However, limited evidence about the spatial relationships shared between ancestral human (hominin) remains, edible resources, refuge, and freshwater leaves the influence of local resources on our species' evolution open to debate. Exceptionally well-preserved organic geochemical fossils-biomarkers-preserved in a soil horizon resolve different plant communities at meter scales across a contiguous 25,000 m 2 archaeological land surface at Olduvai Gorge from about 2 Ma. Biomarkers reveal hominins had access to aquatic plants and protective woods in a patchwork landscape, which included a spring-fed wetland near a woodland that both were surrounded by open grassland. Numerous cut-marked animal bones are located within the wooded area, and within meters of wetland vegetation delineated by biomarkers for ferns and sedges. Taken together, plant biomarkers, clustered bone debris, and hominin remains define a clear spatial pattern that places animal butchery amid the refuge of an isolated forest patch and near freshwater with diverse edible resources.biomarker | leaf wax | carbon isotope | paleoecology | human evolution S patial patterns in archaeological remains provide a glimpse into the lives of our ancestors (1-5). Although many early hominin environments are interpreted as grassy or open woodlands (6-8), fossil bones and plant remains are rarely preserved together in the same settings. As a result, associated landscape reconstructions commonly lack coexisting fossil evidence for hominins and local-scale habitat (microhabitat) that defined the distribution of plant foods, refuge, and water (7). This problem is exacerbated by the discontinuous nature and low time resolution often available across ancient soil (paleosol) horizons, including hominin archaeological localities. One notable exception is welltime-correlated 1.8-million-y-old paleosol horizons exposed at Olduvai Gorge. Associated horizons contain exceptionally preserved plant biomarkers along with many artifacts and fossilized bones. Plant biomarkers, which previously revealed temporal patterns in vegetation and water (8), are well preserved in the paleosol horizon and document plant-type spatial distributions that provide an ecosystem context (9, 10) for resources that likely affected the diets and behavior of hominin inhabitants.Plant biomarkers are delivered by litter to soils and can distinguish plant functional type differences in standing biomass over scales of 1-1,000 m 2 (11). Trees, grasses, and other terrestrial plants produce leaf waxes that include long-chain n-alkanes such as hentriacontane (nC 31 ), whereas aquatic plants and phytoplankton produce midchain homologs (e.g., nC 23 ) (12, 13). The ratio of shorter-versus long-chain n-alkane abundances distinguish relative organic matter inputs from aquatic versus terrestrial plants to sediments (13): Lignin monomers provide evidence for woody and nonwoody plants. This refracto...

show abstract

Section: Significancementioning

confidence: 99%

mentioning

confidence: 99%

Dietary options and behavior suggested by plant biomarker evidence in an early human habitat

Magill

Ashley

Domı́nguez-Rodrigo

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Their significance in part derives from their occurrence in a midPliocene interval (approximately 3.8-3.6 Ma) poorly represented elsewhere in Africa by fossil proboscideans (Sanders et al 2010). The only other substantial African fossil proboscidean assemblages of this age derive from the Upper Laetolil Beds at Laetoli, Tanzania, dated to 3.85-3.63 Ma (Beden 1987b;Deino 2011;Sanders 2005Sanders , 2011, and from the Shabeley Laag Mb. of the Mount Galili Fm.…”

Section: Discussionmentioning

confidence: 99%

A New Assemblage of Mid-Pliocene Proboscideans from the Woranso-Mille Area, Afar Region, Ethiopia: Taxonomic, Evolutionary, and Paleoecological Considerations

Sanders

Haile‐Selassie

2011

J Mammal Evol

View full text Add to dashboard Cite

Recent fieldwork at Woranso-Mille, Ethiopia led to the recovery of an abundant, diverse mammalian fauna that includes remains of the early hominid Australopithecus afarensis. Proboscideans are among the taxa well sampled at the site, primarily by gnathodental specimens, dated to the mid-Pliocene interval of 3.8-3.6 Ma. These fossils document traces of the last anancine gomphotheres (Anancus ultimus) in eastern Africa and several elephant taxa. Comparative study of the elephant fossils indicates the presence of cf. Mammuthus sp. "Hadar-type," cf. Elephas ekorensis, E. recki brumpti, and cf. Loxodonta adaurora adaurora. Proboscidean evolution in the mid-Pliocene is interesting because during this time archaic elephants were completely replaced by basal members of crown elephant lineages, taxonomic diversity was high (multiple elephant species, anancine gomphotheres, stegodonts, and deinotheres), and elephants were undergoing substantial reorganization of the craniodental masticatory apparatus, presumably in response to the spread of more open habitats and greater competition for grazing resources. The Woranso-Mille sample is important because this interval is only represented elsewhere in eastern Africa by a small number of sites, and because adaptive diversification among early crown elephants requires greater clarification. Morphometric contrasts among the fossil dentition from Woranso-Mille presage the differential success of elephant lineages in eastern Africa during the Pleistocene, providing hints about the beginnings of competitive displacement. Differences between E. recki brumpti from WoransoMille and the slightly younger Sidi Hakoma Member of the Hadar Formation reveal the beginnings of continuous, directional morphometric change that characterized the lineage. Reconsideration of E. recki subspecies indicates that they are arbitrary lineage divisions tied to geochronological boundaries (with utility for biochronological correlation at well sampled sites) rather than real phylogenetic entities, but does not reject monophyly or anagenetic evolution of the lineage.

show abstract

“…The large volcanic complex has a number of volcanoes that erupted periodically over the last 5 myr. Most are dormant, although one, Ol Doinyo Lengai, is currently active (Dawson, 2008;Deino, 2012). Extensional tectonics and volcanism are part of a regional response to the ongoing development of the EARS Dawson, 2008;Le Gall et al, 2008;Mollel & Swisher, 2012).…”

Section: Geologymentioning

confidence: 99%

“…Olduvai Gorge was incised in the Late Pleistocene by a river system that now drains eastward towards the Highlands. The basin's welldated tuffs allow basin-wide correlation of widely separated outcrops and dating of archaeological sites (Hay, 1976;Blumenschine et al, 2003;McHenry, 2005;Deino, 2012;Dom ınguez-Rodrigo et al, 2012). Rift-related extensional tectonics segmented the Olduvai stratigraphy into blocks separated mainly by normal faults (Hay, 1976).…”

Section: Geologymentioning

confidence: 99%

Subtle signatures of seeps: Record of groundwater in a Dryland,DK, Olduvai Gorge, Tanzania

Ashley

Wet

Barboni

et al. 2016

The Depositional Record

View full text Add to dashboard Cite

Few proxies exist to identify aridity in the depositional record, although drylands cover ca 30% of the modern continental surface. New exposures in a siliciclastic and carbonate sequence in an arid to hyperarid basin at Olduvai Gorge, Tanzania provide a unique multi-proxy record of a 1Á85 Ma landscape that was exploited by early humans. The 2 m thick sequence of clastics and carbonates that are exposed along a 450 m outcrop records climate change over a single precession (dry-wet-dry) cycle. Siliciclastic data (sedimentary structures, grain size, mineralogy) and biological data are combined with data for a 10 to 35 cm thick limestone (stable isotopes, elemental geochemistry, petrography) to generate a depositional facies model for a site DK (Douglass Korongo) on this dry rift basin landscape. This site was situated on a low gradient, distal portion of a volcaniclastic alluvial fan. The clastics are intercalated distal alluvial fan sandy silts and lake clays that accumulated in a low energy environment. Groundwater discharge and the alkaline springs and seeps during wet-to-dry change in climate made a freshwater carbonate-rich environment. Bedded lithofacies (a lime mudstone with fossils) were deposited in shallow standing (spring-fed) pools, while nodular lithofacies with calcite spherulites indicate permanently saturated ground (seeps). Both environments experienced similar diagenesis, that is, the precipitation of authigenic barite from supersaturated groundwater, desiccation and pedogenesis, and late-stage calcite precipitation. Compositional and isotopic data suggest that a fresh groundwater-fed system was available to early humans even during dry intervals of the precession cycle.

show abstract

Geochronology

Cited by 11 publications

References 50 publications

Dietary options and behavior suggested by plant biomarker evidence in an early human habitat

Dietary options and behavior suggested by plant biomarker evidence in an early human habitat

A New Assemblage of Mid-Pliocene Proboscideans from the Woranso-Mille Area, Afar Region, Ethiopia: Taxonomic, Evolutionary, and Paleoecological Considerations

Subtle signatures of seeps: Record of groundwater in a Dryland,DK, Olduvai Gorge, Tanzania

Contact Info

Product

Resources

About