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Skip to Search Results- 1Barr, Braden N.
- 1Bell, Phil
- 1Buckley, Lisa G
- 1Croghan, Jasmine A.
- 1Dyer, Aaron David
- 1Fagua Gonzalez, Giovanny
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Fall 2018
A full understanding of the evolution of novel forms requires inference about their origins through the study of variation in extant taxa and clues from the fossil record. However, the origins of morphological diversity in many groups are obscured by the scarcity of transitional fossils or...
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Spring 2015
Pachyrhinosaurus is a peculiar ceratopsian known only from Upper Cretaceous strata of Alberta and the North Slope of Alaska. The genus consists of three described species Pachyrhinosaurus canadensis, Pachyrhinosaurus lakustai, and Pachyrhinosaurus perotorum that are distinguishable by cranial...
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Critical analysis of the factors affecting the "cranial suture aging method" using the Hamann Todd Collection
DownloadFall 2014
Cranial suture closure has been regarded as an unreliable method for age estimation due to the large amount of variability in the commencement, progression and termination of fusion. A preliminary study done on the J.C.B. Grant Collection (University of Toronto; Toronto, Ontario) showed that...
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Two New Species and a Revised Phylogeny of the Ellimmichthyiformes (Teleostei: Clupeomorpha)
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The Ellimmichthyiformes is an extinct order of clupeomorph fishes. This group includes fossil species from marine, estuarine, and freshwater sediments ranging in time from the Early Cretaceous to the Eocene. In spite of the long history of taxonomic studies on the Clupeomorpha, phylogenetic...
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Systematics of an Oligocene-Aged Fossil Snake Assemblage from the White River Formation, Wyoming
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Extinct snake taxa are primarily recognized from isolated vertebrae. A new specimen from the Oligocene of Wyoming provides a rare opportunity to examine four nearly complete and articulated fossil snakes. Informally assigned previously to the ‘erycine’ vertebral form taxa Ogmophis and...
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An Evaluation of Embalmed Cadaveric Human Tissue in the Investigation of Multiple Freeze and Thaw Cycles on the Histological Morphology of Human Bone
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Our understanding of the myriad of possible taphonomic agents acting on remains in a forensic context has dramatically increased over the last two decades (Haglund and Sorg, 2002); however, the effects of cold temperature on the microstructure of bone tissue are still not well understood. Recent...
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Comparative Analysis of the Anatomy of the Myxinoidea and the Ancestry of Early Vertebrate Lineages
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The question of whether a hagfish is a true vertebrate or not has profound implications about the ancestry of the clade. New anatomical evidence allows a test of their systematic position. With dissections and serial sections of original specimens, and with a literature review, a comparative...
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A molecular assessment of range expansion of the northern or virile crayfish (Orconectes virilis), crayfish-based community co-structure, and phylogeny of crayfish-affiliated symbionts
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Geographical limits of a species’ range are determined in part by the environmental tolerances of that species, and also by its past and current ability to colonize new areas. Range shifts are a common occurrence in the evolutionary history of almost all taxa; however, anthropogenically-mediated...
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Spring 2020
The human bony pelvis is important in many anthropological studies of archaeological populations and of human evolution as it balances two important human characteristics: upright walking and the birthing of large-brained infants. While it has been thought that the female pelvis is selectively...