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Research paper thumbnail of Wiley-Blackwell Encyclopedia of Human Evolution

Papers by Robyn Pickering

Research paper thumbnail of Newly discovered fossil- and artifact-bearing deposits, uranium-series ages, and Plio-Pleistocene hominids at Swartkrans Cave, South Africa

We report on new research at Swartkrans Cave, South Africa, that provides evidence of two previou... more We report on new research at Swartkrans Cave, South Africa, that provides evidence of two previously unrealized artifact- and fossil-bearing deposits. These deposits underlie a speleothem dated by the uranium-thorium disequilibrium technique to 110,000 +- 1,980 years old, the first tightly constrained, geochronological date available for the site. Recovered fauna from the two underlying deposits – including, prominently, the dental remains of Paranthropus (Australopithecus) robustus from the uppermost layer (Talus Cone Deposit) – indicate a significantly older, late Pliocene or early Pleistocene age for these units. The lowest unit (LB East Extension) is inferred to be an eastward extension of the well-known Lower Bank of Member 1, the earliest surviving infill represented at the site. The date acquired from the speleothem also sets the maximum age of a rich Middle Stone Age lithic assemblage.

Research paper thumbnail of 1.32 ± 0.11 Ma age for underwater remains constrain antiquity and longevity of the Dominican primate Antillothrix bernensis

Journal of Human Evolution

Endemic New World monkeys are an important element of the extinct mammal faunas of the Caribbean'... more Endemic New World monkeys are an important element of the extinct mammal faunas of the Caribbean's Greater Antilles. Here we report the first geochronometric evidence that the primate Antillothrix bernensis existed in the Dominican Republic during the Pleistocene, based on the uranium-series age of carbonate speleothem that encased a tibia when it was collected in a flooded cave. Three-dimensional geometric morphometrics of laser-scanned living and extinct samples provide evidence to support the hypothesis that this specimen and other Dominican primate tibial remains belong to that same species. U–Th dating of the host cave carbonate returns ages consistently at the 600 ka upper limit of the technique. However, U–Pb, capable of resolving ages of greater antiquity, is more robust in this context, returning a secure age of 1.32 ± 0.11 Ma, which is the oldest chronometric age recorded for a Hispaniolan mammal. While its origins and manner and time of arrival are obscure, the morphometric studies are consistent with phylogenetic analyses that place A. bernensis within the pitheciid clade of the platyrrhines. The species apparently endured for over 1 million years during the climatic perturbations of the Pleistocene, as a frugivorous climbing quadruped, one of two known primate species occupying the hazard prone island of Hispaniola.

Research paper thumbnail of at 1.977 Ma and Implications for the Origins Australopithecus sediba

Newly exposed cave sediments at the Malapa site include a flowstone layer capping the sedimentary... more Newly exposed cave sediments at the Malapa site include a flowstone layer capping the sedimentary unit containing the Australopithecus sediba fossils. Uranium-lead dating of the flowstone, combined with paleomagnetic and stratigraphic analysis of the flowstone and underlying sediments, provides a tightly constrained date of 1.977 T 0.002 million years ago (Ma) for these fossils. This refined dating suggests that Au. sediba from Malapa predates the earliest uncontested evidence for Homo in Africa.

Research paper thumbnail of Australopithecus sediba at 1.977 Ma and Implications for the Origins of the Genus Homo

Research paper thumbnail of Contemporary flowstone development links early hominin bearing cave deposits in South Africa

Research paper thumbnail of U–Pb dating of calcite–aragonite layers in speleothems from hominin sites in South Africa by MC-ICP-MS.

Research paper thumbnail of New Australopithecus Robustus Fossils and Associated U-PB Dates From Cooper's Cave (Gauteng, South Africa)

Journal of human …, Jan 1, 2009

Research paper thumbnail of Geological Setting and Age of Australopithecus Sediba From Southern Africa

Research paper thumbnail of A re-appraisal of the stratigraphy and new U-Pb dates at the Sterkfontein hominin site, South Africa.

Research paper thumbnail of Timing and climatic impact of Greenland interstadials recorded in stalagmites from northern Turkey.

Research paper thumbnail of Probable Human Hair Found In a Fossil Hyaena Coprolite From Gladysvale Cave, South Africa

Journal of …, Jan 1, 2009

Research paper thumbnail of A Mid-Pleistocene in situ fossil brown hyaena (Parahyaena brunnea) latrine from Gladysvale Cave, South Africa.

Research paper thumbnail of Newly discovered fossil-and artifact-bearing deposits, uranium-series ages, and Plio-Pleistocene hominids at Swartkrans Cave, South Africa

Journal of human …, Jan 1, 2009

We report on new research at Swartkrans Cave, South Africa, that provides evidence of two previou... more We report on new research at Swartkrans Cave, South Africa, that provides evidence of two previously unrealized artifact-and fossil-bearing deposits. These deposits underlie a speleothem dated by the uranium-thorium disequilibrium technique to 110,000 AE 1,980 years old, the first tightly constrained, geochronological date available for the site. Recovered fauna from the two underlying depositsdincluding, prominently, the dental remains of Paranthropus (Australopithecus) robustus from the uppermost layer (Talus Cone Deposit)dindicate a significantly older, late Pliocene or early Pleistocene age for these units. The lowest unit (LB East Extension) is inferred to be an eastward extension of the well-known Lower Bank of Member 1, the earliest surviving infill represented at the site. The date acquired from the speleothem also sets the maximum age of a rich Middle Stone Age lithic assemblage. (T.R. Pickering). 1 Unless monophyly of the robust australopithecines can be established more convincingly, TRP and JLH object to the use of Paranthropus robustus and instead prefer the use of Australopithecus robustus. However, to conform to the current inclination of many specialists, including RJC, we employ the designation P. robustus throughout the rest of this paper.

Research paper thumbnail of Recent developments in Quaternary dating methods.

Research paper thumbnail of Stratigraphy, U-Th Chronology, and Paleoenvironments at Gladysvale Cave: Insights Into the Climatic Control of South African Hominin-Bearing Cave Deposits

Journal of human …, Jan 1, 2007

Research paper thumbnail of Unravelling the evolution of an Alpine to post-glacially active fault in the Swiss Alps

Journal of Structural …, Jan 1, 2007

The Gemmi fault is a prominent NWeSE striking lineament that crosses the Gemmi Pass in the centra... more The Gemmi fault is a prominent NWeSE striking lineament that crosses the Gemmi Pass in the central Swiss Alps. A multidisciplinary investigation of this structure that included geological mapping, joint profiling, cathodoluminescence and scanning electron microscopy, stable isotope measurements, luminescence-and U-TH-dating, 3D ground penetrating radar (GPR) surveying and trenching reveals a history of fault movements from the Miocene to the Holocene. The main fault zone comprises a 0.5e3 m thick calcite cataclasite formed during several cycles of veining and brittle deformation. Displaced Cretaceous rock layers show an apparent dextral slip of w10 m along the fault.

Research paper thumbnail of Regional geology, setting and sedimentology of Sibudu Cave

South Afr Humanit, Jan 1, 2006

Sibudu Cave has rich, well preserved Middle Stone Age deposits with a centimetre-scale stratigrap... more Sibudu Cave has rich, well preserved Middle Stone Age deposits with a centimetre-scale stratigraphy. The fine-grained, ashy sediments lack sedimentary structures and contain abundant cultural material (stone tools in particular); this implies that the deposits are of anthropogenic origin. The space available for occupation, and for accumulation of deposit, is controlled by the morphology of the floor. This is seen in the similarity between the dip angles of the wall and the layers of the deposit. The archaeological deposits are concentrated in the sheltered northern part of the shelter, where the most suitable space is available.

Research paper thumbnail of The stratigraphy, chronology and palaeoenvironment of the Pleistocene cave fill, Gladysvale Cave, South Africa

Research paper thumbnail of GSSA Student Rep.@ LARGE

Research paper thumbnail of Wiley-Blackwell Encyclopedia of Human Evolution

Research paper thumbnail of Newly discovered fossil- and artifact-bearing deposits, uranium-series ages, and Plio-Pleistocene hominids at Swartkrans Cave, South Africa

We report on new research at Swartkrans Cave, South Africa, that provides evidence of two previou... more We report on new research at Swartkrans Cave, South Africa, that provides evidence of two previously unrealized artifact- and fossil-bearing deposits. These deposits underlie a speleothem dated by the uranium-thorium disequilibrium technique to 110,000 +- 1,980 years old, the first tightly constrained, geochronological date available for the site. Recovered fauna from the two underlying deposits – including, prominently, the dental remains of Paranthropus (Australopithecus) robustus from the uppermost layer (Talus Cone Deposit) – indicate a significantly older, late Pliocene or early Pleistocene age for these units. The lowest unit (LB East Extension) is inferred to be an eastward extension of the well-known Lower Bank of Member 1, the earliest surviving infill represented at the site. The date acquired from the speleothem also sets the maximum age of a rich Middle Stone Age lithic assemblage.

Research paper thumbnail of 1.32 ± 0.11 Ma age for underwater remains constrain antiquity and longevity of the Dominican primate Antillothrix bernensis

Journal of Human Evolution

Endemic New World monkeys are an important element of the extinct mammal faunas of the Caribbean'... more Endemic New World monkeys are an important element of the extinct mammal faunas of the Caribbean's Greater Antilles. Here we report the first geochronometric evidence that the primate Antillothrix bernensis existed in the Dominican Republic during the Pleistocene, based on the uranium-series age of carbonate speleothem that encased a tibia when it was collected in a flooded cave. Three-dimensional geometric morphometrics of laser-scanned living and extinct samples provide evidence to support the hypothesis that this specimen and other Dominican primate tibial remains belong to that same species. U–Th dating of the host cave carbonate returns ages consistently at the 600 ka upper limit of the technique. However, U–Pb, capable of resolving ages of greater antiquity, is more robust in this context, returning a secure age of 1.32 ± 0.11 Ma, which is the oldest chronometric age recorded for a Hispaniolan mammal. While its origins and manner and time of arrival are obscure, the morphometric studies are consistent with phylogenetic analyses that place A. bernensis within the pitheciid clade of the platyrrhines. The species apparently endured for over 1 million years during the climatic perturbations of the Pleistocene, as a frugivorous climbing quadruped, one of two known primate species occupying the hazard prone island of Hispaniola.

Research paper thumbnail of at 1.977 Ma and Implications for the Origins Australopithecus sediba

Newly exposed cave sediments at the Malapa site include a flowstone layer capping the sedimentary... more Newly exposed cave sediments at the Malapa site include a flowstone layer capping the sedimentary unit containing the Australopithecus sediba fossils. Uranium-lead dating of the flowstone, combined with paleomagnetic and stratigraphic analysis of the flowstone and underlying sediments, provides a tightly constrained date of 1.977 T 0.002 million years ago (Ma) for these fossils. This refined dating suggests that Au. sediba from Malapa predates the earliest uncontested evidence for Homo in Africa.

Research paper thumbnail of Australopithecus sediba at 1.977 Ma and Implications for the Origins of the Genus Homo

Research paper thumbnail of Contemporary flowstone development links early hominin bearing cave deposits in South Africa

Research paper thumbnail of U–Pb dating of calcite–aragonite layers in speleothems from hominin sites in South Africa by MC-ICP-MS.

Research paper thumbnail of New Australopithecus Robustus Fossils and Associated U-PB Dates From Cooper's Cave (Gauteng, South Africa)

Journal of human …, Jan 1, 2009

Research paper thumbnail of Geological Setting and Age of Australopithecus Sediba From Southern Africa

Research paper thumbnail of A re-appraisal of the stratigraphy and new U-Pb dates at the Sterkfontein hominin site, South Africa.

Research paper thumbnail of Timing and climatic impact of Greenland interstadials recorded in stalagmites from northern Turkey.

Research paper thumbnail of Probable Human Hair Found In a Fossil Hyaena Coprolite From Gladysvale Cave, South Africa

Journal of …, Jan 1, 2009

Research paper thumbnail of A Mid-Pleistocene in situ fossil brown hyaena (Parahyaena brunnea) latrine from Gladysvale Cave, South Africa.

Research paper thumbnail of Newly discovered fossil-and artifact-bearing deposits, uranium-series ages, and Plio-Pleistocene hominids at Swartkrans Cave, South Africa

Journal of human …, Jan 1, 2009

We report on new research at Swartkrans Cave, South Africa, that provides evidence of two previou... more We report on new research at Swartkrans Cave, South Africa, that provides evidence of two previously unrealized artifact-and fossil-bearing deposits. These deposits underlie a speleothem dated by the uranium-thorium disequilibrium technique to 110,000 AE 1,980 years old, the first tightly constrained, geochronological date available for the site. Recovered fauna from the two underlying depositsdincluding, prominently, the dental remains of Paranthropus (Australopithecus) robustus from the uppermost layer (Talus Cone Deposit)dindicate a significantly older, late Pliocene or early Pleistocene age for these units. The lowest unit (LB East Extension) is inferred to be an eastward extension of the well-known Lower Bank of Member 1, the earliest surviving infill represented at the site. The date acquired from the speleothem also sets the maximum age of a rich Middle Stone Age lithic assemblage. (T.R. Pickering). 1 Unless monophyly of the robust australopithecines can be established more convincingly, TRP and JLH object to the use of Paranthropus robustus and instead prefer the use of Australopithecus robustus. However, to conform to the current inclination of many specialists, including RJC, we employ the designation P. robustus throughout the rest of this paper.

Research paper thumbnail of Recent developments in Quaternary dating methods.

Research paper thumbnail of Stratigraphy, U-Th Chronology, and Paleoenvironments at Gladysvale Cave: Insights Into the Climatic Control of South African Hominin-Bearing Cave Deposits

Journal of human …, Jan 1, 2007

Research paper thumbnail of Unravelling the evolution of an Alpine to post-glacially active fault in the Swiss Alps

Journal of Structural …, Jan 1, 2007

The Gemmi fault is a prominent NWeSE striking lineament that crosses the Gemmi Pass in the centra... more The Gemmi fault is a prominent NWeSE striking lineament that crosses the Gemmi Pass in the central Swiss Alps. A multidisciplinary investigation of this structure that included geological mapping, joint profiling, cathodoluminescence and scanning electron microscopy, stable isotope measurements, luminescence-and U-TH-dating, 3D ground penetrating radar (GPR) surveying and trenching reveals a history of fault movements from the Miocene to the Holocene. The main fault zone comprises a 0.5e3 m thick calcite cataclasite formed during several cycles of veining and brittle deformation. Displaced Cretaceous rock layers show an apparent dextral slip of w10 m along the fault.

Research paper thumbnail of Regional geology, setting and sedimentology of Sibudu Cave

South Afr Humanit, Jan 1, 2006

Sibudu Cave has rich, well preserved Middle Stone Age deposits with a centimetre-scale stratigrap... more Sibudu Cave has rich, well preserved Middle Stone Age deposits with a centimetre-scale stratigraphy. The fine-grained, ashy sediments lack sedimentary structures and contain abundant cultural material (stone tools in particular); this implies that the deposits are of anthropogenic origin. The space available for occupation, and for accumulation of deposit, is controlled by the morphology of the floor. This is seen in the similarity between the dip angles of the wall and the layers of the deposit. The archaeological deposits are concentrated in the sheltered northern part of the shelter, where the most suitable space is available.

Research paper thumbnail of The stratigraphy, chronology and palaeoenvironment of the Pleistocene cave fill, Gladysvale Cave, South Africa

Research paper thumbnail of GSSA Student Rep.@ LARGE

Research paper thumbnail of STUDENT GEOCONGRESS From the Organising Committee