The Giant Beaver (Castoroides ohioensis) was the largest ice age rodent in North America, reachin... more The Giant Beaver (Castoroides ohioensis) was the largest ice age rodent in North America, reaching about the size of a Black Bear (Ursus americanus). In Canada, fossils of this species are commonly found in the Old Crow Basin, Yukon, and single specimens are known from Toronto, Ontario and Indian Island, New Brunswick. A hitherto overlooked 1891 record of a Giant Beaver skull from near Highgate, Ontario is the earliest for Canada.
Proboscidean limb bones discovered in Yukon during the 1960s and 1970s exhibit fracture patterns,... more Proboscidean limb bones discovered in Yukon during the 1960s and 1970s exhibit fracture patterns, notches, and bone flakes that are characteristic of percussion. Because of the unique properties of thick cortical proboscidean bone (probably woolly mammoth Mammuthus primigenius or less likely American mastodon Mammut americanum), some researchers hypothesized that these fracture patterns represent intentional hammerstone modification by humans for marrow extraction and bone tool production. As such, these fracture patterns represent evidence of early human dispersal into Eastern Beringia. Radiocarbon dating in the late 1980s indicated that the bone breakage occurred between about 25 000 and 40 000 radiocarbon years before present (14C yr BP). We report 11 new radiocarbon ages using ultra-filtration methods on a different sample of similarly fractured and flaked bones from Yukon. Only two of the radiocarbon ages fall within the expected range of 25 000 to 40 000 14C yr BP. Six other a...
Fragmentary but massive left and right horncores, found with eight post-cranial bones, from a cla... more Fragmentary but massive left and right horncores, found with eight post-cranial bones, from a clay unit underlying a diamicton of the last (Fraser) glaciation at Chuchi Lake, British Columbia probably represents an individual giant bison (Bison cf. B. latifrons). A sample of bone from one of the horncores yielded an accelerator mass spectrometry (AMS) radiocarbon date of 30 740 ± 220 BP, whereas overlapping dates from two other laboratories on an associated humerus are 34 800 ± 420 BP and 35 480 ± 1080 BP. Despite the discrepancy between horncore and humerus dates, they are in accord with the suspected stratigraphie age of the clay unit whence they came. Analysis of pollen from that clay unit indicates that bison with massive horns once occupied an open forest in the vicinity. Probably giant bison and Columbian mammoths (incorporating paleoenvironmental evidence found with the nearby, penecontemporaneous Babine Lake mammoth) shared lake-dotted open forest to shrub tundra range in wh...
Vertebrate fossils and faunas that are reasonably inferred to be of last (Sangamonian) interglaci... more Vertebrate fossils and faunas that are reasonably inferred to be of last (Sangamonian) interglacial age are considered in geographic order from east to west to north in Canada. Data on localities, vertebrate taxa, stratigraphy, geochronology, paleoenvironment and paleoclimate are considered. Information on key faunas from Toronto, Fort Qu'Appelle, Saskatoon. Medicine Hat and Old Crow River is supplemented by data on smaller faunas and, in some cases, individual specimens. New data are included for several localities. Fishes, such as whitefish (Coregonus sp.) and pike (Esox sp.). had broad distributions from eastern to northwestern Canada. Except for a turtle (Emydoidea blandingi) from lnnerkip, Ontario, amphibians and reptiles have not yet been reported from Canada during the Sangamon Interglaciation. Several species of grouse-like birds (Tetraonidae) are known from western Canada. Among the mammals. American mastodons (Mammut americanum), mammoths (Mammuthus sp.), beavers (Cast...
A nearly complete, articulated skeleton of an old white whale (Delphinapterus leucas) from Champl... more A nearly complete, articulated skeleton of an old white whale (Delphinapterus leucas) from Champlain Sea deposits at Saint-Félix-de-Valois is the best preserved specimen of its kind recorded from North America. It is one of 21 white whale specimens known from Champlain Sea deposits. Collagen from a vertebra yielded an accelerator mass spectrometry radiocarbon date of 10 700 ± 90 BP, which, with stratigraphic and paleoenvironmental data, is in accord with our knowledge of the past distribution of this species, its known habitat and habits. This study quantitatively traces regional sea-surface temperature, salinity and ice-cover. Dinocysts indicate a change from cold to cool conditions in surface water during that period corresponding to the withdrawal of ice and the beginning of the Holocene.
The only representative of the extinct North American megafauna known from Québec is an American ... more The only representative of the extinct North American megafauna known from Québec is an American mastodon from Pointe de Chambord, Lac-Saint-Jean. Marine mammals have played a prominent part in our knowledge of the Quaternary vertebrates of Québec since Per Kalm was informed of a whale skeleton found inland from the St. Lawrence River about 1749. Five species of whales particularly adapted to inshore conditions have been reported from Late-glacial deposits of Champlain Sea age. The bones represent mainly white whales, but also narwhals, harbour porpoise, humpback, common finback and bowhead whales. Seals (ringed, harp, bearded and harbour) have also been discovered, and walrus remains are known from Sainte-Julienne-de-Montcalm and Saint-Nicolas. Sandpits at Saint-Nicolas (bottom-dwelling fishes, seabirds, ringed seal and white whale) and Saint-Césaire (fish, eider duck, ringed seal and white whale) have yielded important Champlain Sea vertebrate fossils, as well as paleoenvironmenta...
Remains of Middle Wisconsinan mammoth, bison, horse, moose, hare, ground squirrel and lemming wer... more Remains of Middle Wisconsinan mammoth, bison, horse, moose, hare, ground squirrel and lemming were recovered from sediments that stratigraphically underlie till of the Late Wisconsinan McConnell Glaciation along the Ketza River valley. The bone-bearing sediments are a complex of colluvium, fan, and outwash sediments. Similar fossil sites are likely to occur where glaciofluvial watercourses abut hillside deposits laid down prior to the onset of McConnell Glaciation.
Arctisorex polaris, gen.n., sp.n., from the late Neogene of Ellesmere Island, Nunavut, is the mos... more Arctisorex polaris, gen.n., sp.n., from the late Neogene of Ellesmere Island, Nunavut, is the most northerly record thus far of a shrew. The genus is represented by the posterior moiety of a dentary and last two molars. The well-developed M3 and the extreme distance between the articular condyles, separated by a narrow interarticular isthmus, agrees best with the neomyine shrews. The expansion and anterior inclination of the coronoid process, extreme elongation of the third molar that results in it being longer than the M2, and the M3 with a distinct entoconid valley, are unique among soricids. We suggest that Arctisorex may be the only shrew specialized for frugivory.
The Bering Land Bridge connecting North America and Eurasia was periodically exposed and inundate... more The Bering Land Bridge connecting North America and Eurasia was periodically exposed and inundated by oscillating sea levels during the Pleistocene glacial cycles. This land connection allowed the intermittent dispersal of animals, including humans, between Western Beringia (far north-east Asia) and Eastern Beringia (north-west North America), changing the faunal community composition of both continents. The Pleistocene glacial cycles also had profound impacts on temperature, precipitation, and vegetation, impacting faunal community structure and demography. While these paleoenvironmental impacts have been studied in many large herbivores from Beringia (e.g., bison, mammoths, horses), the Pleistocene population dynamics of the diverse guild of carnivorans present in the region are less well understood, due to their lower abundances. In this study, we analyze mitochondrial genome data from ancient brown bears (Ursus arctos; n = 103) and lions (Panthera spp.; n = 39), two megafaunal c...
The skeletal remains of a small bear (Protarctos abstrusus) were collected at the Beaver Pond fos... more The skeletal remains of a small bear (Protarctos abstrusus) were collected at the Beaver Pond fossil site in the High Arctic (Ellesmere I., Nunavut). This mid-Pliocene deposit has also yielded 12 other mammals and the remains of a boreal-forest community. Phylogenetic analysis reveals this bear to be basal to modern bears. It appears to represent an immigration event from Asia, leaving no living North American descendants. The dentition shows only modest specialization for herbivory, consistent with its basal position within Ursinae. However, the appearance of dental caries suggest a diet high in fermentable-carbohydrates. Fossil plants remains, including diverse berries, suggests that, like modern northern black bears, P. abstrusus may have exploited a high-sugar diet in the fall to promote fat accumulation and facilitate hibernation. A tendency toward a sugar-rich diet appears to have arisen early in Ursinae, and may have played a role in allowing ursine lineages to occupy cold ha...
Proceedings of the National Academy of Sciences, 2014
Significance New radiocarbon ( 14 C) dates on American mastodon ( Mammut americanum ) fossils in ... more Significance New radiocarbon ( 14 C) dates on American mastodon ( Mammut americanum ) fossils in Alaska and Yukon suggest this species suffered local extirpation before terminal Pleistocene climate changes or human colonization. Mastodons occupied high latitudes during the Last Interglacial (∼125,000–75,000 y ago) when forests were established. Ecological changes during the Wisconsinan glaciation (∼75,000 y ago) led to habitat loss and population collapse. Thereafter, mastodons were limited to areas south of the continental ice sheets, where they ultimately died out ∼10,000 14 C years B.P. Extirpation of mastodons and some other megafaunal species in high latitudes was thus independent of their later extinction south of the ice. Rigorous pretreatment was crucial to removing contamination from fossils that originally yielded erroneously “young” 14 C dates.
The widespread extinctions of large mammals at the end of the Pleistocene epoch have often been a... more The widespread extinctions of large mammals at the end of the Pleistocene epoch have often been attributed to the depredations of humans; here we present genetic evidence that questions this assumption. We used ancient DNA and Bayesian techniques to reconstruct a detailed genetic history of bison throughout the late Pleistocene and Holocene epochs. Our analyses depict a large diverse population living throughout Beringia until around 37,000 years before the present, when the population's genetic diversity began to decline dramatically. The timing of this decline correlates with environmental changes associated with the onset of the last glacial cycle, whereas archaeological evidence does not support the presence of large populations of humans in Eastern Beringia until more than 15,000 years later.
A peat deposit on Ellesmere Island, Nunavut, Canada, allows a unique glimpse of the Early Pliocen... more A peat deposit on Ellesmere Island, Nunavut, Canada, allows a unique glimpse of the Early Pliocene terrestrial biota north of the Arctic Circle. The peat accumulated in a beaver pond surrounded by boreal larch forest near regional tree line in coastal hills close to the Arctic Ocean. The ecological affinities of the plant and beetle remains contained in the peat indicate that winter temperatures on Ellesmere Island were nearly 15 degrees C higher and summer temperatures 10 degrees C higher than they are today. Here we show that the mammalian remains buried in the peat represent mainly taxa of Eurasiatic zoogeographic and phyletic affinities, including the first North American occurrence of a meline badger (Arctomeles). This deposit contains direct evidence of the composition of an Early Pliocene (4-5 million years ago) arctic mammalian fauna during an active period of interchange between Asia and North America.
The Giant Beaver (Castoroides ohioensis) was the largest ice age rodent in North America, reachin... more The Giant Beaver (Castoroides ohioensis) was the largest ice age rodent in North America, reaching about the size of a Black Bear (Ursus americanus). In Canada, fossils of this species are commonly found in the Old Crow Basin, Yukon, and single specimens are known from Toronto, Ontario and Indian Island, New Brunswick. A hitherto overlooked 1891 record of a Giant Beaver skull from near Highgate, Ontario is the earliest for Canada.
Proboscidean limb bones discovered in Yukon during the 1960s and 1970s exhibit fracture patterns,... more Proboscidean limb bones discovered in Yukon during the 1960s and 1970s exhibit fracture patterns, notches, and bone flakes that are characteristic of percussion. Because of the unique properties of thick cortical proboscidean bone (probably woolly mammoth Mammuthus primigenius or less likely American mastodon Mammut americanum), some researchers hypothesized that these fracture patterns represent intentional hammerstone modification by humans for marrow extraction and bone tool production. As such, these fracture patterns represent evidence of early human dispersal into Eastern Beringia. Radiocarbon dating in the late 1980s indicated that the bone breakage occurred between about 25 000 and 40 000 radiocarbon years before present (14C yr BP). We report 11 new radiocarbon ages using ultra-filtration methods on a different sample of similarly fractured and flaked bones from Yukon. Only two of the radiocarbon ages fall within the expected range of 25 000 to 40 000 14C yr BP. Six other a...
Fragmentary but massive left and right horncores, found with eight post-cranial bones, from a cla... more Fragmentary but massive left and right horncores, found with eight post-cranial bones, from a clay unit underlying a diamicton of the last (Fraser) glaciation at Chuchi Lake, British Columbia probably represents an individual giant bison (Bison cf. B. latifrons). A sample of bone from one of the horncores yielded an accelerator mass spectrometry (AMS) radiocarbon date of 30 740 ± 220 BP, whereas overlapping dates from two other laboratories on an associated humerus are 34 800 ± 420 BP and 35 480 ± 1080 BP. Despite the discrepancy between horncore and humerus dates, they are in accord with the suspected stratigraphie age of the clay unit whence they came. Analysis of pollen from that clay unit indicates that bison with massive horns once occupied an open forest in the vicinity. Probably giant bison and Columbian mammoths (incorporating paleoenvironmental evidence found with the nearby, penecontemporaneous Babine Lake mammoth) shared lake-dotted open forest to shrub tundra range in wh...
Vertebrate fossils and faunas that are reasonably inferred to be of last (Sangamonian) interglaci... more Vertebrate fossils and faunas that are reasonably inferred to be of last (Sangamonian) interglacial age are considered in geographic order from east to west to north in Canada. Data on localities, vertebrate taxa, stratigraphy, geochronology, paleoenvironment and paleoclimate are considered. Information on key faunas from Toronto, Fort Qu'Appelle, Saskatoon. Medicine Hat and Old Crow River is supplemented by data on smaller faunas and, in some cases, individual specimens. New data are included for several localities. Fishes, such as whitefish (Coregonus sp.) and pike (Esox sp.). had broad distributions from eastern to northwestern Canada. Except for a turtle (Emydoidea blandingi) from lnnerkip, Ontario, amphibians and reptiles have not yet been reported from Canada during the Sangamon Interglaciation. Several species of grouse-like birds (Tetraonidae) are known from western Canada. Among the mammals. American mastodons (Mammut americanum), mammoths (Mammuthus sp.), beavers (Cast...
A nearly complete, articulated skeleton of an old white whale (Delphinapterus leucas) from Champl... more A nearly complete, articulated skeleton of an old white whale (Delphinapterus leucas) from Champlain Sea deposits at Saint-Félix-de-Valois is the best preserved specimen of its kind recorded from North America. It is one of 21 white whale specimens known from Champlain Sea deposits. Collagen from a vertebra yielded an accelerator mass spectrometry radiocarbon date of 10 700 ± 90 BP, which, with stratigraphic and paleoenvironmental data, is in accord with our knowledge of the past distribution of this species, its known habitat and habits. This study quantitatively traces regional sea-surface temperature, salinity and ice-cover. Dinocysts indicate a change from cold to cool conditions in surface water during that period corresponding to the withdrawal of ice and the beginning of the Holocene.
The only representative of the extinct North American megafauna known from Québec is an American ... more The only representative of the extinct North American megafauna known from Québec is an American mastodon from Pointe de Chambord, Lac-Saint-Jean. Marine mammals have played a prominent part in our knowledge of the Quaternary vertebrates of Québec since Per Kalm was informed of a whale skeleton found inland from the St. Lawrence River about 1749. Five species of whales particularly adapted to inshore conditions have been reported from Late-glacial deposits of Champlain Sea age. The bones represent mainly white whales, but also narwhals, harbour porpoise, humpback, common finback and bowhead whales. Seals (ringed, harp, bearded and harbour) have also been discovered, and walrus remains are known from Sainte-Julienne-de-Montcalm and Saint-Nicolas. Sandpits at Saint-Nicolas (bottom-dwelling fishes, seabirds, ringed seal and white whale) and Saint-Césaire (fish, eider duck, ringed seal and white whale) have yielded important Champlain Sea vertebrate fossils, as well as paleoenvironmenta...
Remains of Middle Wisconsinan mammoth, bison, horse, moose, hare, ground squirrel and lemming wer... more Remains of Middle Wisconsinan mammoth, bison, horse, moose, hare, ground squirrel and lemming were recovered from sediments that stratigraphically underlie till of the Late Wisconsinan McConnell Glaciation along the Ketza River valley. The bone-bearing sediments are a complex of colluvium, fan, and outwash sediments. Similar fossil sites are likely to occur where glaciofluvial watercourses abut hillside deposits laid down prior to the onset of McConnell Glaciation.
Arctisorex polaris, gen.n., sp.n., from the late Neogene of Ellesmere Island, Nunavut, is the mos... more Arctisorex polaris, gen.n., sp.n., from the late Neogene of Ellesmere Island, Nunavut, is the most northerly record thus far of a shrew. The genus is represented by the posterior moiety of a dentary and last two molars. The well-developed M3 and the extreme distance between the articular condyles, separated by a narrow interarticular isthmus, agrees best with the neomyine shrews. The expansion and anterior inclination of the coronoid process, extreme elongation of the third molar that results in it being longer than the M2, and the M3 with a distinct entoconid valley, are unique among soricids. We suggest that Arctisorex may be the only shrew specialized for frugivory.
The Bering Land Bridge connecting North America and Eurasia was periodically exposed and inundate... more The Bering Land Bridge connecting North America and Eurasia was periodically exposed and inundated by oscillating sea levels during the Pleistocene glacial cycles. This land connection allowed the intermittent dispersal of animals, including humans, between Western Beringia (far north-east Asia) and Eastern Beringia (north-west North America), changing the faunal community composition of both continents. The Pleistocene glacial cycles also had profound impacts on temperature, precipitation, and vegetation, impacting faunal community structure and demography. While these paleoenvironmental impacts have been studied in many large herbivores from Beringia (e.g., bison, mammoths, horses), the Pleistocene population dynamics of the diverse guild of carnivorans present in the region are less well understood, due to their lower abundances. In this study, we analyze mitochondrial genome data from ancient brown bears (Ursus arctos; n = 103) and lions (Panthera spp.; n = 39), two megafaunal c...
The skeletal remains of a small bear (Protarctos abstrusus) were collected at the Beaver Pond fos... more The skeletal remains of a small bear (Protarctos abstrusus) were collected at the Beaver Pond fossil site in the High Arctic (Ellesmere I., Nunavut). This mid-Pliocene deposit has also yielded 12 other mammals and the remains of a boreal-forest community. Phylogenetic analysis reveals this bear to be basal to modern bears. It appears to represent an immigration event from Asia, leaving no living North American descendants. The dentition shows only modest specialization for herbivory, consistent with its basal position within Ursinae. However, the appearance of dental caries suggest a diet high in fermentable-carbohydrates. Fossil plants remains, including diverse berries, suggests that, like modern northern black bears, P. abstrusus may have exploited a high-sugar diet in the fall to promote fat accumulation and facilitate hibernation. A tendency toward a sugar-rich diet appears to have arisen early in Ursinae, and may have played a role in allowing ursine lineages to occupy cold ha...
Proceedings of the National Academy of Sciences, 2014
Significance New radiocarbon ( 14 C) dates on American mastodon ( Mammut americanum ) fossils in ... more Significance New radiocarbon ( 14 C) dates on American mastodon ( Mammut americanum ) fossils in Alaska and Yukon suggest this species suffered local extirpation before terminal Pleistocene climate changes or human colonization. Mastodons occupied high latitudes during the Last Interglacial (∼125,000–75,000 y ago) when forests were established. Ecological changes during the Wisconsinan glaciation (∼75,000 y ago) led to habitat loss and population collapse. Thereafter, mastodons were limited to areas south of the continental ice sheets, where they ultimately died out ∼10,000 14 C years B.P. Extirpation of mastodons and some other megafaunal species in high latitudes was thus independent of their later extinction south of the ice. Rigorous pretreatment was crucial to removing contamination from fossils that originally yielded erroneously “young” 14 C dates.
The widespread extinctions of large mammals at the end of the Pleistocene epoch have often been a... more The widespread extinctions of large mammals at the end of the Pleistocene epoch have often been attributed to the depredations of humans; here we present genetic evidence that questions this assumption. We used ancient DNA and Bayesian techniques to reconstruct a detailed genetic history of bison throughout the late Pleistocene and Holocene epochs. Our analyses depict a large diverse population living throughout Beringia until around 37,000 years before the present, when the population's genetic diversity began to decline dramatically. The timing of this decline correlates with environmental changes associated with the onset of the last glacial cycle, whereas archaeological evidence does not support the presence of large populations of humans in Eastern Beringia until more than 15,000 years later.
A peat deposit on Ellesmere Island, Nunavut, Canada, allows a unique glimpse of the Early Pliocen... more A peat deposit on Ellesmere Island, Nunavut, Canada, allows a unique glimpse of the Early Pliocene terrestrial biota north of the Arctic Circle. The peat accumulated in a beaver pond surrounded by boreal larch forest near regional tree line in coastal hills close to the Arctic Ocean. The ecological affinities of the plant and beetle remains contained in the peat indicate that winter temperatures on Ellesmere Island were nearly 15 degrees C higher and summer temperatures 10 degrees C higher than they are today. Here we show that the mammalian remains buried in the peat represent mainly taxa of Eurasiatic zoogeographic and phyletic affinities, including the first North American occurrence of a meline badger (Arctomeles). This deposit contains direct evidence of the composition of an Early Pliocene (4-5 million years ago) arctic mammalian fauna during an active period of interchange between Asia and North America.
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Papers by C. Richard Harington