Taxonomy, location of origin, and health status of proboscideans from Western Canada investigated using stable isotope analysis

We investigated the application of stable isotope analysis of proboscidean remains (collagen in bone/dentin/cementum and structural carbonate in enamel bioapatite) for genus-level identification of isolated specimens, assessment of geographic origins, and testing for nutritional stress. Mammoths (Mammuthus sp.) tended to have higher δ15Ncol and lower δ13Ccol than mastodons (Mammut americanum), but differences were not significant in every location. Determining the genus of isolated specimens may be possible for locations and time periods with good isotopic baselines, but environmental changes can confound interpretations. For example, an Alberta proboscidean with a δ15Ncol of +1.4‰ (characteristic of mastodons) ultimately proved to be a mammoth. Its surprisingly low nitrogen isotope composition is attributable to the recently deglaciated environment it inhabited. We provided a baseline for isotopic assessment of geographic origins of isolated proboscideans in Western Canada. Bioapatite δ13Csc and δ18Osc can be used to distinguish specimens from Alberta, Klondike, Old Crow, Herschel Island, and further south (e.g., Arizona, Great Lakes). Finally, we found that an Alberta mammoth with morphological evidence of nutritional stress experienced a change in diet, environment, or physiology prior to death, but its isotopic compositions did not suggest a link to hypothesized starvation (catabolism of proteins or reliance on lipids)

American Mastodon Mitochondrial Genomes Suggest Multiple Dispersal Events in Response to Pleistocene Climate Oscillations

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 testable hypotheses for extant species expected to experience substantial biogeographic impacts from rising temperatures

Evolution of the Family Equidae, Subfamily Equinae, in North, Central and South America, Eurasia and Africa during the Plio-Pleistocene

Studies of horse evolution arose during the middle of the 19th century, and several hypotheses have been proposed for their taxonomy, paleobiogeography, paleoecology and evolution. The present contribution represents a collaboration of 19 multinational experts with the goal of providing an updated summary of Pliocene and Pleistocene North, Central and South American, Eurasian and African horses. At the present time, we recognize 114 valid species across these continents, plus 4 North African species in need of further investigation. Our biochronology and biogeography sections integrate Equinae taxonomic records with their chronologic and geographic ranges recognizing regional biochronologic frameworks. The paleoecology section provides insights into paleobotany and diet utilizing both the mesowear and light microscopic methods, along with calculation of body masses. We provide a temporal sequence of maps that render paleoclimatic conditions across these continents integrated with Equinae occurrences. These records reveal a succession of extinctions of primitive lineages and the rise and diversification of more modern taxa. Two recent morphological-based cladistic analyses are presented here as competing hypotheses, with reference to molecular-based phylogenies. Our contribution represents a state-of-the art understanding of Plio-Pleistocene Equus evolution, their biochronologic and biogeographic background and paleoecological and paleoclimatic contexts

Evolution of the Family Equidae, Subfamily Equinae, in North, Central and South America, Eurasia and Africa during the Plio-Pleistocene

Studies of horse evolution arose during the middle of the 19th century, and several hypotheses have been proposed for their taxonomy, paleobiogeography, paleoecology and evolution. The present contribution represents a collaboration of 19 multinational experts with the goal of providing an updated summary of Pliocene and Pleistocene North, Central and South American, Eurasian and African horses. At the present time, we recognize 114 valid species across these continents, plus 4 North African species in need of further investigation. Our biochronology and biogeography sections integrate Equinae taxonomic records with their chronologic and geographic ranges recognizing regional biochronologic frameworks. The paleoecology section provides insights into paleobotany and diet utilizing both the mesowear and light microscopic methods, along with calculation of body masses. We provide a temporal sequence of maps that render paleoclimatic conditions across these continents integrated with Equinae occurrences. These records reveal a succession of extinctions of primitive lineages and the rise and diversification of more modern taxa. Two recent morphological-based cladistic analyses are presented here as competing hypotheses, with reference to molecular-based phylogenies. Our contribution represents a state-of-the art understanding of Plio-Pleistocene Equus evolution, their biochronologic and biogeographic background and paleoecological and paleoclimatic contexts

Evolution of the Family Equidae, Subfamily Equinae, in North, Central and South America, Eurasia and Africa during the Plio-Pleistocene

Studies of horse evolution arose during the middle of the 19th century, and several hypotheses have been proposed for their taxonomy, paleobiogeography, paleoecology and evolution. The present contribution represents a collaboration of 19 multinational experts with the goal of providing an updated summary of Pliocene and Pleistocene North, Central and South American, Eurasian and African horses. At the present time, we recognize 114 valid species across these continents, plus 4 North African species in need of further investigation. Our biochronology and biogeography sections integrate Equinae taxonomic records with their chronologic and geographic ranges recognizing regional biochronologic frameworks. The paleoecology section provides insights into paleobotany and diet utilizing both the mesowear and light microscopic methods, along with calculation of body masses. We provide a temporal sequence of maps that render paleoclimatic conditions across these continents integrated with Equinae occurrences. These records reveal a succession of extinctions of primitive lineages and the rise and diversification of more modern taxa. Two recent morphological-based cladistic analyses are presented here as competing hypotheses, with reference to molecular-based phylogenies. Our contribution represents a state-of-the art understanding of Plio-Pleistocene Equus evolution, their biochronologic and biogeographic background and paleoecological and paleoclimatic contexts. © 2022 by the authors.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

High Tumour Cannabinoid CB1 Receptor Immunoreactivity Negatively Impacts Disease-Specific Survival in Stage II Microsatellite Stable Colorectal Cancer

BACKGROUND: There is good evidence in the literature that the cannabinoid system is disturbed in colorectal cancer. In the present study, we have investigated whether CB(1) receptor immunoreactive intensity (CB(1)IR intensity) is associated with disease severity and outcome. METHODOLOGY/PRINCIPAL FINDINGS: CB(1)IR was assessed in formalin-fixed, paraffin-embedded specimens collected with a consecutive intent during primary tumour surgical resection from a series of cases diagnosed with colorectal cancer. Tumour centre (n = 483) and invasive front (n = 486) CB(1)IR was scored from 0 (absent) to 3 (intense staining) and the data was analysed as a median split i.e. CB(1)IR <2 and ≥2. In microsatellite stable, but not microsatellite instable tumours (as adjudged on the basis of immunohistochemical determination of four mismatch repair proteins), there was a significant positive association of the tumour grade with the CB(1)IR intensity. The difference between the microsatellite stable and instable tumours for this association of CB(1)IR was related to the CpG island methylation status of the cases. Cox proportional hazards regression analyses indicated a significant contribution of CB(1)IR to disease-specific survival in the microsatellite stable tumours when adjusting for tumour stage. For the cases with stage II microsatellite stable tumours, there was a significant effect of both tumour centre and front CB(1)IR upon disease specific survival. The 5 year probabilities of event-free survival were: 85±5 and 66±8%; tumour interior, 86±4% and 63±8% for the CB(1)IR<2 and CB(1)IR≥2 groups, respectively. CONCLUSIONS/SIGNIFICANCE: The level of CB(1) receptor expression in colorectal cancer is associated with the tumour grade in a manner dependent upon the degree of CpG hypermethylation. A high CB(1)IR is indicative of a poorer prognosis in stage II microsatellite stable tumour patients

Pleistocene lagomorphs from Cathedral Cave, Nevada

Faunal data from Cathedral Cave, Nevada, provide insight into biotic changes that occurred within the Great Basin prior to the latest Pleistocene. Taxonomic identifications of lagomorphs from Cathedral Cave were made using a morphological approach intended to minimize geographic and temporal assumptions. Although this approach to identification is conservative, the resultant data set is appropriate for inclusion in future analyses of regional biotic change. Lagomorphs recovered from the site include new regional records of two extinct taxa, Aztlanolagus agilis and Brachylagus coloradoensis. Other lagomorphs from Cathedral Cave include Brachylagus idahoensis, Ochotona sp., and Sylvilagus or Lepus sp. The presence of a posterorinternal reentrant fold on the p3 of some specimens of Ochotona sp. suggests that the range of variation present in the individual teeth of pikas needs to be described in further detail. In contrast to a previously established hypothesis of increasing enamel complexity in the p4 of Aztlanolagus agilis, evaluation of crenulation patterns of Aztlanolagus agilis from Cathedral Cave showed no distinct trends

Pleistocene lagomorphs from Cathedral Cave, Nevada

Faunal data from Cathedral Cave, Nevada, provide insight into biotic changes that occurred within the Great Basin prior to the latest Pleistocene. Taxonomic identifications of lagomorphs from Cathedral Cave were made using a morphological approach intended to minimize geographic and temporal assumptions. Although this approach to identification is conservative, the resultant data set is appropriate for inclusion in future analyses of regional biotic change. Lagomorphs recovered from the site include new regional records of two extinct taxa, Aztlanolagus agilis and Brachylagus coloradoensis. Other lagomorphs from Cathedral Cave include Brachylagus idahoensis, Ochotona sp., and Sylvilagus or Lepus sp. The presence of a posterorinternal reentrant fold on the p3 of some specimens of Ochotona sp. suggests that the range of variation present in the individual teeth of pikas needs to be described in further detail. In contrast to a previously established hypothesis of increasing enamel complexity in the p4 of Aztlanolagus agilis, evaluation of crenulation patterns of Aztlanolagus agilis from Cathedral Cave showed no distinct trends

Camel fossils from gravel pits near Edmonton and Vauxhall, and a review of the Quaternary camelid record of Alberta

Camelid remains are known from several Quaternary palaeontological localities in Alberta, yet most specimens are undescribed in the literature. Specimens reported here comprise a large sample of the known camelid record from the province, and provide further insight into the record of Quaternary megafauna of western Canada. Remains from the Edmonton area include specimens pre- and post-dating the Last Glacial Maximum (LGM), whereas remains from the Vauxhall area are post-LGM. A metapodial fragment of a giant camel originally described as Titanotylopus from the Edmonton area is likely from earlier in the Pleistocene or late Pliocene. Camelid remains are not overly abundant in Alberta, but are widely distributed, having been recovered from several sites across the province. A new radiocarbon date of 11,280±40 14C yr BP on a radioulna of Camelops cf. C. hesternus represents only the fourth direct age assessment of a Quaternary camelid from Alberta. Radiocarbon data may suggest linkages to patterns of extirpation observed in camelid populations from northern Canada, followed by re-colonization following deglaciation. Key Words: Pleistocene, Camelops, Camelidae, biogeography, radiocarbon datingThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Postglacial Faunal Records From Cave Deposits In Jasper National Park, Alberta, Canada

In 2009, we initiated an on-going, long term research project that focuses on exploration of fossil-bearing cave deposits in Jasper National Park. Specifically, we were interested in understanding patterns of mammalian re-colonization of mountainous regions following late Pleistocene deglaciation. Our work has focused on the identification of fossil-bearing cave deposits, excavation and sampling of those deposits, and radiocarbon dating of recovered remains. Examined sites have at least an age of 9600 years BP. Research at four cave sites, located in relatively close proximity to one another, is contributing to an improved understanding of the late Quaternary record of Jasper National Park. This project is an example of a cooperating partnership between institutions (museum, national park and technical college) and assistance from a speleological society