Chris Widga | Penn State University (original) (raw)

Papers by Chris Widga

Geological Society of America Abstracts with Programs

Quaternary Science Reviews

Current Research in the Pleistocene, 2011

Geological Society of America Abstracts with Programs, 2018

Geological Society of America Abstracts with Programs, 2019

Journal of Veterinary Anatomy, 2015

Scapular skeletal remains of six 20 th century dingoes (Canis lupus dingo) were examined. One had... more Scapular skeletal remains of six 20 th century dingoes (Canis lupus dingo) were examined. One had been an elderly zoo resident, and five were taken in the wild. The zoo specimen and one wild-caught specimen each revealed an unusual bilateral ossified feature of the scapular glenoid fossa. The roughly triangular feature is visually similar to the appearance of a SLAP tear (glenoid superior labral tear, anterior-posterior) in humans. However, the SLAP tear injury is not compatible with current understanding of biceps tendon attachment on the domestic dog scapula. Additionally, the pattern of lateral peri-articular rimming in these six specimens suggests possible incipient pathological change. We discuss the differential diagnoses for these observations.

Geological Society of America Abstracts with Programs, 2019

The extinct woolly mammoth (Mammuthus primigenius) ranged from Alaska to the Northeastern Seaboar... more The extinct woolly mammoth (Mammuthus primigenius) ranged from Alaska to the Northeastern Seaboard throughout the Late Pleistocene (100-10 Ka). Although it is recognized that woolly known about their behavior with respect to activities like migration and dietary preferences in Midwestern mammoths by analyzing stable isotopes of carbon, oxygen, and strontium preserved in the tooth enamel of these extinct elephantids. A woolly mammoth tooth from Moline, IL, was bulk-sampled and micromilled to extract the aforementioned isotopes from the base of the enamel. Dated to 16,410 ±110 BP (20,085-19,530 calBP), measured δ 13 C (-12.6‰ to-11.1‰, VPDB) values indicate that the terminal LGM (Last Glacial Maximum) landscape of western Illinois was dominated by C3 vegetation, which is typical of a cooler climate. This cooler climate during δ 18 O values. However, resulting δ 18 O values (-10.8‰ to-8.1‰, VPDB) are less negative than should be expected. The ratios of 87 Sr/ 86 Sr isotopes retained in the tooth enamel were mapped using GIS onto a regional isoscape to determine the mobility of one mammoth across its lifetime. The mobility patterns were compared to seasonal and annual dietary shifts to better understand any underlying causes for migrations. Preliminary analyses of the 87 Sr/ 86 Sr values (0.7907-0.7156) suggest that there were regional population movements around the northern Mississippi River Valley. The data reveals the climate and landscape during the terminal Pleistocene in western Illinois and how woolly mammoths responded to it.

Journal of Archaeological Science: Reports, 2017

Abstract In 2013, two Pleistocene megafaunal remains, a single mammoth tooth and a partial juveni... more Abstract In 2013, two Pleistocene megafaunal remains, a single mammoth tooth and a partial juvenile mastodon mandible with teeth were recovered by a scallop-fisherman from two separate locations in the Merrimack River embayment off the coast of New Hampshire and Massachusetts. These specimens follow on previous finds by fishermen in the same locale over the last two decades, as well as numerous other offshore megafauna specimens and prehistoric stone tools, which have occurred in the Gulf of Maine for > 50 years. This paper examines the value and scientific sampling potential of previously recovered specimens and isolated finds in the Gulf of Maine. Specifically, it discusses isolated finds as indicators of submerged archaeological site preservation in the region, and as data sources that provide information about regional geomorphology, climate conditions, paleogenomics, and species extinctions in the terminal Pleistocene. Furthermore, submerged paleo-deltas, due to their depositional characteristics, are identified to have deeply buried paleosols with significant preservation potential for early human and environmental history. Therefore, the Merrimack River paleo-delta, and similar offshore submerged features elsewhere, serve not only as research opportunities into early human migration and settlement, but are also storehouses of climate and environmental data, which merit special recognition and protection from environmental and man-made activities that may impact or disturb these intact submerged landscapes.

The Nye site, discovered in 1934 and introduced to the scientifi c community in 1935, offers a si... more The Nye site, discovered in 1934 and introduced to the scientifi c community in 1935, offers a sidelong view of how a post-Folsom Early Man investigation played out beyond the Great Plains in a mound-centric intellectual context. Here, prominent cultural anthropologist-turned-archaeologist Albert Ernest Jenks at the University of Minnesota almost singlehandedly fronted Early Man studies in the region. Prompted and sustained by an astounding streak of good fortune, Jenks embraced multidisciplinary studies of sites between 1931 and his retirement in 1938. At Nye, extinct bison remains and purported artifacts were recovered from peat by a dragline excavator used to haul the underlying marl to the surface. Failure to prepare a fi nal (and timely) report muzzled the site in subsequent Early Man discussions. Study of the extant bison remains, including radiocarbon measurement and stable isotope analysis, indicate northwestern Wisconsin supported resident bison during the early and middle ...

The Anatomical Record, 2021

We evaluated coxofemoral joints from museum specimens of: Vulpes lagopus; Vulpes vulpes; Vulpes v... more We evaluated coxofemoral joints from museum specimens of: Vulpes lagopus; Vulpes vulpes; Vulpes velox; Nyctereutes procyonoides; Urocyon cinereoargenteus; Aenocyon [Canis] dirus; Canis latrans; Canis lupus lupus; Canis lupus familiaris; C. l. familiaris x latrans; and Canis dingo. Acetabular components included: fossa; articular surface; medial and lateral articular margins; and peri-articular surfaces. Acetabular components variably revealed: osteophyte-like features; varying appearance of articular margin rims (especially contour changes); rough bone surfaces (especially fossa and articular surface); and surface wear. Proximal femoral components included: articular surface; articular margin; peri-articular surfaces; and joint capsule attachment. Femoral components variably revealed: rough bone surface; bone loss; articular margin osteophyte-like features (AMO); caudal post-developmental mineralized prominence (PMP); and enthesophytes along the joint capsule attachment. Non-metric multidimensional scaling (NMDS) was used to analyze right-left asymmetric relationships between observed traits, across taxa. Significantly different acetabular trait asymmetry involved only C. latrans - C. l. familiaris; V. vulpes - N. procyonoides, and U. cinereoargenteus - N. procyonoides. There were no significant lateralized differences in proximal femoral traits involving modern canids, ancient and modern C. l. familiaris, or modern vulpines. Thus, the observations were strongly bilateral. We hypothesized high similarity of traits across taxa. The data confirm the hypothesis and strongly suggest broad and deep morphological and mechanistic conservation that almost certainly pre-existed (at least) all modern canids. Further zoological studies are needed to evaluate phylogenic implications in greater detail. This article is protected by copyright. All rights reserved.

This is the project page for a custom, sub-millimeter resolution, micromill capable of milling ve... more This is the project page for a custom, sub-millimeter resolution, micromill capable of milling vertical samples through mammoth tooth enamel.

Global Ecology and Biogeography, 2020

Mammoth Cave guano deposits contain a rich record of troglofauna spanning the last 125,000 years.... more Mammoth Cave guano deposits contain a rich record of troglofauna spanning the last 125,000 years. In particular, chiropteran remains from Chief City provide insight into ecosystem dynamics of the cave area during the last interglacial. This paper presents results of paleontological excavations undertaken in 2008. Sub-fossil remains (N=1134) in Chief City guano deposits are dominated by chiropteran taxa. Although all identifi ed taxa are extant, the combination of Myotis leibii and Tadarida brasiliensis is an association without modern analogue. Stable isotope analyses of guano indicate a C3 prey signature characteristic of forested habitat. This was unexpected given the prevalence of T. brasiliensis, a species that is typically associated with open environments. Ecomorphological consideration of wing shape trends in these assemblages indicate that interglacial faunas are dominated by fast-fl ying, open-space taxa (T. brasiliensis) while late Holocene and Historic assemblages contain...

Plains Anthropologist, 2020

Since its excavation almost four decades ago, the Lange/Ferguson site in western South Dakota has... more Since its excavation almost four decades ago, the Lange/Ferguson site in western South Dakota has been considered a classic example of Clovis mammoth utilization. Over the years the site’s principa...

Nature Communications, 2020

Pleistocene glacial-interglacial cycles are correlated with dramatic temperature oscillations. Ex... more Pleistocene glacial-interglacial cycles are correlated with dramatic temperature oscillations. Examining how species responded to these natural fluctuations can provide valuable insights into the impacts of present-day anthropogenic climate change. Here we present a phylogeographic study of the extinct American mastodon (Mammut americanum), based on 35 complete mitochondrial genomes. These data reveal the presence of multiple lineages within this species, including two distinct clades from eastern Beringia. Our molecular date estimates suggest that these clades arose at different times, supporting a pattern of repeated northern expansion and local extirpation in response to glacial cycling. Consistent with this hypothesis, we also note lower levels of genetic diversity among northern mastodons than in endemic clades south of the continental ice sheets. The results of our study highlight the complex relationships between population dispersals and climate change, and can provide testa...

Quaternary Research, 2020

Stable isotopes of mammoths and mastodons have the potential to illuminate ecological changes in ... more Stable isotopes of mammoths and mastodons have the potential to illuminate ecological changes in late Pleistocene landscapes and megafaunal populations as these species approached extinction. The ecological factors at play in this extinction remain unresolved, but isotopes of bone collagen (δ13C, δ15N) and tooth enamel (δ13C, δ18O, 87Sr/86Sr) from midwestern North America are leveraged to examine ecological and behavioral changes that occurred during the last interglacial-glacial cycle. Both species had significant C3 contributions to their diets and experienced increasing levels of niche overlap as they approached extinction. A subset of mastodons after the last glacial maximum exhibit low δ15N values that may represent expansion into a novel ecological niche, perhaps densely occupied by other herbivores. Stable isotopes from serial and microsampled enamel show increasing seasonality and decreasing temperatures as mammoths transitioned from Marine Isotope Stage (MIS) 5e to glacial ...

Geological Society of America Abstracts with Programs

Quaternary Science Reviews

Current Research in the Pleistocene, 2011

Geological Society of America Abstracts with Programs, 2018

Geological Society of America Abstracts with Programs, 2019

Journal of Veterinary Anatomy, 2015

Scapular skeletal remains of six 20 th century dingoes (Canis lupus dingo) were examined. One had... more Scapular skeletal remains of six 20 th century dingoes (Canis lupus dingo) were examined. One had been an elderly zoo resident, and five were taken in the wild. The zoo specimen and one wild-caught specimen each revealed an unusual bilateral ossified feature of the scapular glenoid fossa. The roughly triangular feature is visually similar to the appearance of a SLAP tear (glenoid superior labral tear, anterior-posterior) in humans. However, the SLAP tear injury is not compatible with current understanding of biceps tendon attachment on the domestic dog scapula. Additionally, the pattern of lateral peri-articular rimming in these six specimens suggests possible incipient pathological change. We discuss the differential diagnoses for these observations.

Geological Society of America Abstracts with Programs, 2019

The extinct woolly mammoth (Mammuthus primigenius) ranged from Alaska to the Northeastern Seaboar... more The extinct woolly mammoth (Mammuthus primigenius) ranged from Alaska to the Northeastern Seaboard throughout the Late Pleistocene (100-10 Ka). Although it is recognized that woolly known about their behavior with respect to activities like migration and dietary preferences in Midwestern mammoths by analyzing stable isotopes of carbon, oxygen, and strontium preserved in the tooth enamel of these extinct elephantids. A woolly mammoth tooth from Moline, IL, was bulk-sampled and micromilled to extract the aforementioned isotopes from the base of the enamel. Dated to 16,410 ±110 BP (20,085-19,530 calBP), measured δ 13 C (-12.6‰ to-11.1‰, VPDB) values indicate that the terminal LGM (Last Glacial Maximum) landscape of western Illinois was dominated by C3 vegetation, which is typical of a cooler climate. This cooler climate during δ 18 O values. However, resulting δ 18 O values (-10.8‰ to-8.1‰, VPDB) are less negative than should be expected. The ratios of 87 Sr/ 86 Sr isotopes retained in the tooth enamel were mapped using GIS onto a regional isoscape to determine the mobility of one mammoth across its lifetime. The mobility patterns were compared to seasonal and annual dietary shifts to better understand any underlying causes for migrations. Preliminary analyses of the 87 Sr/ 86 Sr values (0.7907-0.7156) suggest that there were regional population movements around the northern Mississippi River Valley. The data reveals the climate and landscape during the terminal Pleistocene in western Illinois and how woolly mammoths responded to it.

Journal of Archaeological Science: Reports, 2017

Abstract In 2013, two Pleistocene megafaunal remains, a single mammoth tooth and a partial juveni... more Abstract In 2013, two Pleistocene megafaunal remains, a single mammoth tooth and a partial juvenile mastodon mandible with teeth were recovered by a scallop-fisherman from two separate locations in the Merrimack River embayment off the coast of New Hampshire and Massachusetts. These specimens follow on previous finds by fishermen in the same locale over the last two decades, as well as numerous other offshore megafauna specimens and prehistoric stone tools, which have occurred in the Gulf of Maine for > 50 years. This paper examines the value and scientific sampling potential of previously recovered specimens and isolated finds in the Gulf of Maine. Specifically, it discusses isolated finds as indicators of submerged archaeological site preservation in the region, and as data sources that provide information about regional geomorphology, climate conditions, paleogenomics, and species extinctions in the terminal Pleistocene. Furthermore, submerged paleo-deltas, due to their depositional characteristics, are identified to have deeply buried paleosols with significant preservation potential for early human and environmental history. Therefore, the Merrimack River paleo-delta, and similar offshore submerged features elsewhere, serve not only as research opportunities into early human migration and settlement, but are also storehouses of climate and environmental data, which merit special recognition and protection from environmental and man-made activities that may impact or disturb these intact submerged landscapes.

The Nye site, discovered in 1934 and introduced to the scientifi c community in 1935, offers a si... more The Nye site, discovered in 1934 and introduced to the scientifi c community in 1935, offers a sidelong view of how a post-Folsom Early Man investigation played out beyond the Great Plains in a mound-centric intellectual context. Here, prominent cultural anthropologist-turned-archaeologist Albert Ernest Jenks at the University of Minnesota almost singlehandedly fronted Early Man studies in the region. Prompted and sustained by an astounding streak of good fortune, Jenks embraced multidisciplinary studies of sites between 1931 and his retirement in 1938. At Nye, extinct bison remains and purported artifacts were recovered from peat by a dragline excavator used to haul the underlying marl to the surface. Failure to prepare a fi nal (and timely) report muzzled the site in subsequent Early Man discussions. Study of the extant bison remains, including radiocarbon measurement and stable isotope analysis, indicate northwestern Wisconsin supported resident bison during the early and middle ...

The Anatomical Record, 2021

We evaluated coxofemoral joints from museum specimens of: Vulpes lagopus; Vulpes vulpes; Vulpes v... more We evaluated coxofemoral joints from museum specimens of: Vulpes lagopus; Vulpes vulpes; Vulpes velox; Nyctereutes procyonoides; Urocyon cinereoargenteus; Aenocyon [Canis] dirus; Canis latrans; Canis lupus lupus; Canis lupus familiaris; C. l. familiaris x latrans; and Canis dingo. Acetabular components included: fossa; articular surface; medial and lateral articular margins; and peri-articular surfaces. Acetabular components variably revealed: osteophyte-like features; varying appearance of articular margin rims (especially contour changes); rough bone surfaces (especially fossa and articular surface); and surface wear. Proximal femoral components included: articular surface; articular margin; peri-articular surfaces; and joint capsule attachment. Femoral components variably revealed: rough bone surface; bone loss; articular margin osteophyte-like features (AMO); caudal post-developmental mineralized prominence (PMP); and enthesophytes along the joint capsule attachment. Non-metric multidimensional scaling (NMDS) was used to analyze right-left asymmetric relationships between observed traits, across taxa. Significantly different acetabular trait asymmetry involved only C. latrans - C. l. familiaris; V. vulpes - N. procyonoides, and U. cinereoargenteus - N. procyonoides. There were no significant lateralized differences in proximal femoral traits involving modern canids, ancient and modern C. l. familiaris, or modern vulpines. Thus, the observations were strongly bilateral. We hypothesized high similarity of traits across taxa. The data confirm the hypothesis and strongly suggest broad and deep morphological and mechanistic conservation that almost certainly pre-existed (at least) all modern canids. Further zoological studies are needed to evaluate phylogenic implications in greater detail. This article is protected by copyright. All rights reserved.

This is the project page for a custom, sub-millimeter resolution, micromill capable of milling ve... more This is the project page for a custom, sub-millimeter resolution, micromill capable of milling vertical samples through mammoth tooth enamel.

Global Ecology and Biogeography, 2020

Mammoth Cave guano deposits contain a rich record of troglofauna spanning the last 125,000 years.... more Mammoth Cave guano deposits contain a rich record of troglofauna spanning the last 125,000 years. In particular, chiropteran remains from Chief City provide insight into ecosystem dynamics of the cave area during the last interglacial. This paper presents results of paleontological excavations undertaken in 2008. Sub-fossil remains (N=1134) in Chief City guano deposits are dominated by chiropteran taxa. Although all identifi ed taxa are extant, the combination of Myotis leibii and Tadarida brasiliensis is an association without modern analogue. Stable isotope analyses of guano indicate a C3 prey signature characteristic of forested habitat. This was unexpected given the prevalence of T. brasiliensis, a species that is typically associated with open environments. Ecomorphological consideration of wing shape trends in these assemblages indicate that interglacial faunas are dominated by fast-fl ying, open-space taxa (T. brasiliensis) while late Holocene and Historic assemblages contain...

Plains Anthropologist, 2020

Since its excavation almost four decades ago, the Lange/Ferguson site in western South Dakota has... more Since its excavation almost four decades ago, the Lange/Ferguson site in western South Dakota has been considered a classic example of Clovis mammoth utilization. Over the years the site’s principa...

Nature Communications, 2020

Pleistocene glacial-interglacial cycles are correlated with dramatic temperature oscillations. Ex... more Pleistocene glacial-interglacial cycles are correlated with dramatic temperature oscillations. Examining how species responded to these natural fluctuations can provide valuable insights into the impacts of present-day anthropogenic climate change. Here we present a phylogeographic study of the extinct American mastodon (Mammut americanum), based on 35 complete mitochondrial genomes. These data reveal the presence of multiple lineages within this species, including two distinct clades from eastern Beringia. Our molecular date estimates suggest that these clades arose at different times, supporting a pattern of repeated northern expansion and local extirpation in response to glacial cycling. Consistent with this hypothesis, we also note lower levels of genetic diversity among northern mastodons than in endemic clades south of the continental ice sheets. The results of our study highlight the complex relationships between population dispersals and climate change, and can provide testa...

Quaternary Research, 2020

Stable isotopes of mammoths and mastodons have the potential to illuminate ecological changes in ... more Stable isotopes of mammoths and mastodons have the potential to illuminate ecological changes in late Pleistocene landscapes and megafaunal populations as these species approached extinction. The ecological factors at play in this extinction remain unresolved, but isotopes of bone collagen (δ13C, δ15N) and tooth enamel (δ13C, δ18O, 87Sr/86Sr) from midwestern North America are leveraged to examine ecological and behavioral changes that occurred during the last interglacial-glacial cycle. Both species had significant C3 contributions to their diets and experienced increasing levels of niche overlap as they approached extinction. A subset of mastodons after the last glacial maximum exhibit low δ15N values that may represent expansion into a novel ecological niche, perhaps densely occupied by other herbivores. Stable isotopes from serial and microsampled enamel show increasing seasonality and decreasing temperatures as mammoths transitioned from Marine Isotope Stage (MIS) 5e to glacial ...

3D technology has great potential for distributing virtual fossils among specialists and the publ... more 3D technology has great potential for distributing virtual fossils among specialists and the public. Although technical hurdles for sharing 3D models are no longer significant, a sustained, stable platform for sharing paleontological 3D models with the scientific community and the public has yet to emerge. Researchers and museums are mutual stakeholders in open data distribution efforts. Any successful database will meet unique paleontological metadata needs, as well as accommodate institutional requirements for sensitive locality information and intellectual property. Digital 3D models have the potential to provide authentic educational experiences to many more students than would be possible with physical specimens. If widely distributed, they may also undercut the market in fossils and antiquities. This will be an open discussion of current efforts to create online vertebrate paleontology 3D databases, and will explore requirements for successful sharing of digital 3D data.