Calibrating human population dispersals across Earth’s surface is fundamental to assessing rates ... more Calibrating human population dispersals across Earth’s surface is fundamental to assessing rates and timing of anthropogenic impacts and distinguishing ecological phenomena influenced by humans from those that were not. Here, we describe the Hartley mammoth locality, which dates to 38,900–36,250 cal BP by AMS 14C analysis of hydroxyproline from bone collagen. We accept the standard view that elaborate stone technology of the Eurasian Upper Paleolithic was introduced into the Americas by arrival of the Native American clade ∼16,000 cal BP. It follows that if older cultural sites exist in the Americas, they might only be diagnosed using nuanced taphonomic approaches. We employed computed tomography (CT and μCT) and other state-of-the-art methods that had not previously been applied to investigating ancient American sites. This revealed multiple lines of taphonomic evidence suggesting that two mammoths were butchered using expedient lithic and bone technology, along with evidence diagn...
The Clovis complex dates from 13,050 to 12,750 cal yr B.P. during a time of major environmental c... more The Clovis complex dates from 13,050 to 12,750 cal yr B.P. during a time of major environmental change.
Large-scale changes in global climate at the end of the Pleistocene significantly impacted ecosys... more Large-scale changes in global climate at the end of the Pleistocene significantly impacted ecosystems across North America. However, the pace and scale of biotic turnover in response to both the Younger Dryas cold period and subsequent Holocene rapid warming have been challenging to assess because of the scarcity of well dated fossil and pollen records that covers this period. Here we present an ancient DNA record from Hall’s Cave, Texas, that documents 100 vertebrate and 45 plant taxa from bulk fossils and sediment. We show that local plant and animal diversity dropped markedly during Younger Dryas cooling, but while plant diversity recovered in the early Holocene, animal diversity did not. Instead, five extant and nine extinct large bodied animals disappeared from the region at the end of the Pleistocene. Our findings suggest that climate change affected the local ecosystem in Texas over the Pleistocene-Holocene boundary, but climate change on its own may not explain the disappear...
ABSTRACTAncient DNA (aDNA) sequencing has enabled unprecedented reconstruction of speciation, mig... more ABSTRACTAncient DNA (aDNA) sequencing has enabled unprecedented reconstruction of speciation, migration, and admixture events for extinct taxa1. Outside the permafrost, however, irreversible aDNA post-mortem degradation2 has so far limited aDNA recovery within the ˜0.5 million years (Ma) time range3. Tandem mass spectrometry (MS)-based collagen type I (COL1) sequencing provides direct access to older biomolecular information4, though with limited phylogenetic use. In the absence of molecular evidence, the speciation of several Early and Middle Pleistocene extinct species remain contentious. In this study, we address the phylogenetic relationships of the Eurasian Pleistocene Rhinocerotidae5-7 using ˜1.77 million years (Ma) old dental enamel proteome sequences of a Stephanorhinus specimen from the Dmanisi archaeological site in Georgia (South Caucasus)8. Molecular phylogenetic analyses place the Dmanisi Stephanorhinus as a sister group to the woolly (Coelodonta antiquitatis) and Merck...
14C dates disprove Holocene survival of Pleistocene megafauna in the Pampas and show humans hunte... more 14C dates disprove Holocene survival of Pleistocene megafauna in the Pampas and show humans huntedMegatheriumat 12,600 CAL BP.
Advances in AMS physics and organic geochemistry have revolutionized our ability to establish abs... more Advances in AMS physics and organic geochemistry have revolutionized our ability to establish absolute chronologies on vertebrate fossils. Highly purified collagen, which provides extremely accurate 14C ages, can be extracted from single bones and teeth as small as 50 mg. Combined with measurement precisions of ±15 to 25 years for ages of < 20,000 yr, the direct AMS 14C technique enables fossil deposits to be chronologically dissected at the level of single animals. Analysis of data from a variety of sites in the United States indicates that most excavation levels (analysis units) as small as 10 cm can be time averaged by several thousand years at a minimum, even with the greatest care in excavation and processing of sediments. Time averaging of this magnitude has important implications for fine-scale paleoecological analysis of faunas, especially when compared to high-resolution climate records like those derived from speleothems, ice cores, or marine cores. To this end, we prop...
Hippidions were equids with very distinctive anatomical features. They lived in South America 2.5... more Hippidions were equids with very distinctive anatomical features. They lived in South America 2.5 million years ago (Ma) until their extinction approximately 10 000 years ago. The evolutionary origin of the three known Hippidion morphospecies is still disputed. Based on palaeontological data, Hippidion could have diverged from the lineage leading to modern equids before 10 Ma. In contrast, a much later divergence date, with Hippidion nesting within modern equids, was indicated by partial ancient mitochondrial DNA sequences. Here, we characterized eight Hippidion complete mitochondrial genomes at 3.4-386.3-fold coverage using target-enrichment capture and next-generation sequencing. Our dataset reveals that the two morphospecies sequenced (H. saldiasi and H. principale) formed a monophyletic clade, basal to extant and extinct Equus lineages. This contrasts with previous genetic analyses and supports Hippidion as a distinct genus, in agreement with palaeontological models. We date the...
This letter is a follow up to your March 10, 1999 letter regarding the ARPA permit submitted by D... more This letter is a follow up to your March 10, 1999 letter regarding the ARPA permit submitted by Dr. Gary,Hucldebe,"r;,,"and myself, for on-site geological excavations at the Kennewick Site, Washington. Your 3110/99 letter noted that the permit application was still under review. Because an additional two months have elapsed, I'm asking what is the status of the decision process and when you and I will expect a reply from your headquarters.
Proceedings of the National Academy of Sciences of the United States of America, Jul 18, 2018
Found in 1968, the archaeological site of Anzick, Montana, contains the only known Clovis burial.... more Found in 1968, the archaeological site of Anzick, Montana, contains the only known Clovis burial. Here, the partial remains of a male infant, Anzick-1, were found in association with a Clovis assemblage of over 100 lithic and osseous artifacts-all red-stained with ochre. The incomplete, unstained cranium of an unassociated, geologically younger individual, Anzick-2, was also recovered. Previous chronometric work has shown an age difference between Anzick-1 and the Clovis assemblage (represented by dates from two antler rod samples). This discrepancy has led to much speculation, with some discounting Anzick-1 as Clovis. To resolve this issue, we present the results of a comprehensive radiocarbon dating program that utilized different pretreatment methods on osseous material from the site. Through this comparative approach, we obtained a robust chronometric dataset that suggests that Anzick-1 is temporally coeval with the dated antler rods. This implies that the individual is indeed t...
Contemporaneity of people and the American mastodon (Mammut americanum) at Big Bone Lick, Kentuck... more Contemporaneity of people and the American mastodon (Mammut americanum) at Big Bone Lick, Kentucky, has been extensively debated for more than two hundred years. Newly interpreted stratigraphic excavations and direct AMS ¹⁴C measurements on mastodon bones from Big Bone Lick, Kentucky, indicate that the megafauna are a palimpsest of fossils spanning at least 1,200 calendar years (11,020 ± 30 to 12,210 ± 35 RC yr B.P.). The radiocarbon evidence indicates that mastodons and Clovis people overlapped in time; however, other than one fossil with a possible cut mark and Clovis artifacts that are physically associated with but dispersed within the bone-bearing deposits, there is no incontrovertible evidence that humans hunted Mammut americanum at the site.
Bone would seem to be an ideal material for14C dating because this calcified tissue contains 20 w... more Bone would seem to be an ideal material for14C dating because this calcified tissue contains 20 weight per cent protein. Fossil bone, however, can lose most of its original organic matter and frequently contains contaminants having different14C ages. Numerous14C dates on bone have been available to archaeologists and geologists but many age determinations have been inaccurate despite over 30 years of research in the field following the first14C age determinations on bone (Arnold & Libby, 1951). This situation remained unchanged until simple pretreatments were abandoned and more bone-specific fractions were isolated. The ideal solution is to use accelerator mass spectrometer14C dating, which facilitates the use of milligram-sized amounts of highly purified compounds—an approach impossible to pursue using conventional14C decay-counting methods.
Calibrating human population dispersals across Earth’s surface is fundamental to assessing rates ... more Calibrating human population dispersals across Earth’s surface is fundamental to assessing rates and timing of anthropogenic impacts and distinguishing ecological phenomena influenced by humans from those that were not. Here, we describe the Hartley mammoth locality, which dates to 38,900–36,250 cal BP by AMS 14C analysis of hydroxyproline from bone collagen. We accept the standard view that elaborate stone technology of the Eurasian Upper Paleolithic was introduced into the Americas by arrival of the Native American clade ∼16,000 cal BP. It follows that if older cultural sites exist in the Americas, they might only be diagnosed using nuanced taphonomic approaches. We employed computed tomography (CT and μCT) and other state-of-the-art methods that had not previously been applied to investigating ancient American sites. This revealed multiple lines of taphonomic evidence suggesting that two mammoths were butchered using expedient lithic and bone technology, along with evidence diagn...
The Clovis complex dates from 13,050 to 12,750 cal yr B.P. during a time of major environmental c... more The Clovis complex dates from 13,050 to 12,750 cal yr B.P. during a time of major environmental change.
Large-scale changes in global climate at the end of the Pleistocene significantly impacted ecosys... more Large-scale changes in global climate at the end of the Pleistocene significantly impacted ecosystems across North America. However, the pace and scale of biotic turnover in response to both the Younger Dryas cold period and subsequent Holocene rapid warming have been challenging to assess because of the scarcity of well dated fossil and pollen records that covers this period. Here we present an ancient DNA record from Hall’s Cave, Texas, that documents 100 vertebrate and 45 plant taxa from bulk fossils and sediment. We show that local plant and animal diversity dropped markedly during Younger Dryas cooling, but while plant diversity recovered in the early Holocene, animal diversity did not. Instead, five extant and nine extinct large bodied animals disappeared from the region at the end of the Pleistocene. Our findings suggest that climate change affected the local ecosystem in Texas over the Pleistocene-Holocene boundary, but climate change on its own may not explain the disappear...
ABSTRACTAncient DNA (aDNA) sequencing has enabled unprecedented reconstruction of speciation, mig... more ABSTRACTAncient DNA (aDNA) sequencing has enabled unprecedented reconstruction of speciation, migration, and admixture events for extinct taxa1. Outside the permafrost, however, irreversible aDNA post-mortem degradation2 has so far limited aDNA recovery within the ˜0.5 million years (Ma) time range3. Tandem mass spectrometry (MS)-based collagen type I (COL1) sequencing provides direct access to older biomolecular information4, though with limited phylogenetic use. In the absence of molecular evidence, the speciation of several Early and Middle Pleistocene extinct species remain contentious. In this study, we address the phylogenetic relationships of the Eurasian Pleistocene Rhinocerotidae5-7 using ˜1.77 million years (Ma) old dental enamel proteome sequences of a Stephanorhinus specimen from the Dmanisi archaeological site in Georgia (South Caucasus)8. Molecular phylogenetic analyses place the Dmanisi Stephanorhinus as a sister group to the woolly (Coelodonta antiquitatis) and Merck...
14C dates disprove Holocene survival of Pleistocene megafauna in the Pampas and show humans hunte... more 14C dates disprove Holocene survival of Pleistocene megafauna in the Pampas and show humans huntedMegatheriumat 12,600 CAL BP.
Advances in AMS physics and organic geochemistry have revolutionized our ability to establish abs... more Advances in AMS physics and organic geochemistry have revolutionized our ability to establish absolute chronologies on vertebrate fossils. Highly purified collagen, which provides extremely accurate 14C ages, can be extracted from single bones and teeth as small as 50 mg. Combined with measurement precisions of ±15 to 25 years for ages of < 20,000 yr, the direct AMS 14C technique enables fossil deposits to be chronologically dissected at the level of single animals. Analysis of data from a variety of sites in the United States indicates that most excavation levels (analysis units) as small as 10 cm can be time averaged by several thousand years at a minimum, even with the greatest care in excavation and processing of sediments. Time averaging of this magnitude has important implications for fine-scale paleoecological analysis of faunas, especially when compared to high-resolution climate records like those derived from speleothems, ice cores, or marine cores. To this end, we prop...
Hippidions were equids with very distinctive anatomical features. They lived in South America 2.5... more Hippidions were equids with very distinctive anatomical features. They lived in South America 2.5 million years ago (Ma) until their extinction approximately 10 000 years ago. The evolutionary origin of the three known Hippidion morphospecies is still disputed. Based on palaeontological data, Hippidion could have diverged from the lineage leading to modern equids before 10 Ma. In contrast, a much later divergence date, with Hippidion nesting within modern equids, was indicated by partial ancient mitochondrial DNA sequences. Here, we characterized eight Hippidion complete mitochondrial genomes at 3.4-386.3-fold coverage using target-enrichment capture and next-generation sequencing. Our dataset reveals that the two morphospecies sequenced (H. saldiasi and H. principale) formed a monophyletic clade, basal to extant and extinct Equus lineages. This contrasts with previous genetic analyses and supports Hippidion as a distinct genus, in agreement with palaeontological models. We date the...
This letter is a follow up to your March 10, 1999 letter regarding the ARPA permit submitted by D... more This letter is a follow up to your March 10, 1999 letter regarding the ARPA permit submitted by Dr. Gary,Hucldebe,"r;,,"and myself, for on-site geological excavations at the Kennewick Site, Washington. Your 3110/99 letter noted that the permit application was still under review. Because an additional two months have elapsed, I'm asking what is the status of the decision process and when you and I will expect a reply from your headquarters.
Proceedings of the National Academy of Sciences of the United States of America, Jul 18, 2018
Found in 1968, the archaeological site of Anzick, Montana, contains the only known Clovis burial.... more Found in 1968, the archaeological site of Anzick, Montana, contains the only known Clovis burial. Here, the partial remains of a male infant, Anzick-1, were found in association with a Clovis assemblage of over 100 lithic and osseous artifacts-all red-stained with ochre. The incomplete, unstained cranium of an unassociated, geologically younger individual, Anzick-2, was also recovered. Previous chronometric work has shown an age difference between Anzick-1 and the Clovis assemblage (represented by dates from two antler rod samples). This discrepancy has led to much speculation, with some discounting Anzick-1 as Clovis. To resolve this issue, we present the results of a comprehensive radiocarbon dating program that utilized different pretreatment methods on osseous material from the site. Through this comparative approach, we obtained a robust chronometric dataset that suggests that Anzick-1 is temporally coeval with the dated antler rods. This implies that the individual is indeed t...
Contemporaneity of people and the American mastodon (Mammut americanum) at Big Bone Lick, Kentuck... more Contemporaneity of people and the American mastodon (Mammut americanum) at Big Bone Lick, Kentucky, has been extensively debated for more than two hundred years. Newly interpreted stratigraphic excavations and direct AMS ¹⁴C measurements on mastodon bones from Big Bone Lick, Kentucky, indicate that the megafauna are a palimpsest of fossils spanning at least 1,200 calendar years (11,020 ± 30 to 12,210 ± 35 RC yr B.P.). The radiocarbon evidence indicates that mastodons and Clovis people overlapped in time; however, other than one fossil with a possible cut mark and Clovis artifacts that are physically associated with but dispersed within the bone-bearing deposits, there is no incontrovertible evidence that humans hunted Mammut americanum at the site.
Bone would seem to be an ideal material for14C dating because this calcified tissue contains 20 w... more Bone would seem to be an ideal material for14C dating because this calcified tissue contains 20 weight per cent protein. Fossil bone, however, can lose most of its original organic matter and frequently contains contaminants having different14C ages. Numerous14C dates on bone have been available to archaeologists and geologists but many age determinations have been inaccurate despite over 30 years of research in the field following the first14C age determinations on bone (Arnold & Libby, 1951). This situation remained unchanged until simple pretreatments were abandoned and more bone-specific fractions were isolated. The ideal solution is to use accelerator mass spectrometer14C dating, which facilitates the use of milligram-sized amounts of highly purified compounds—an approach impossible to pursue using conventional14C decay-counting methods.
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