Item – Theses Canada

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OCLC number
687859129
Link(s) to full text
LAC copy
LAC copy
Author
Scott, Craig Smith,1971-
Title
Late Paleocene mammals from near Red Deer, Alberta, and a phylogenetic analysis of the earliest Lipotyphla (Mammalia, Insectivora).
Degree
Ph. D. -- University of Alberta, 2008
Publisher
Ottawa : Library and Archives Canada = Bibliothèque et Archives Canada, [2009]
Description
15 microfiches
Notes
Includes bibliographical references.
Abstract
Current evidence points to the Paleocene as one of the most important intervals in the evolutionary history of mammals, with the fossil record recording a remarkable adaptive radiation of therians soon after the mass extinctions at the end of the Mesozoic. The taxonomic diversity and systematics of late Paleocene mammals from localities in fossiliferous strata of the Paskapoo Formation in the vicinity of Red Deer, south central Alberta was investigated, with emphasis on the phylogenetic relationships of early Tertiary lipotyphlan insectivorans. Mammals from these localities are more taxonomically diverse than previously understood, with 76 species (24 new) in 51 genera (11 new) recognized among 14 orders. The local faunas are dominated by mammals of small body size, with multituberculates, insectivorans, and plesiadapiforms constituting over 75 percent of the total number of specimens; large mammals are few, represented only by rare specimens of pantodonts and larger-bodied arctocyonid condylarths. Significant discoveries include new genera of a didelphimorphian marsupial, erinaceomorph and soricomorph insectivorans, a viverravid carnivoran, arctocyonid condylarths, titanoideid and cyriacotheriid pantodonts, and a eutherian of uncertain taxonomic position. Other discoveries include the oldest known lipotyphlan petromastoid and postcranium and the first evidence of a venom delivery system in an extinct mammal. New and previously reported material from the Alberta Basin and elsewhere permit the first comprehensive phylogenetic analysis of early Tertiary stem lipotyphlans. While a soricomorph-erinaceomorph dichotomy was recovered, a close association of 'Litolestes, Cedrocherus,' and 'Oncocherus' with extant erinaceids was not supported, nor was inclusion of '"Leptacodon" munusculum' or ' "Leptacodon" packi' with other species of 'Leptacodon.' A new soricomorph genus from the Paleocene of Alberta may represent the first North American record of Amphidozotheriinae, and 'Limaconyssus,' previously considered an aberrant nyctitheriid, is better considered a geolabidid. A preliminary correlation indicates strongest resemblance to the coeval Birchwood local fauna of central Alberta and Cedar Point Quarry local fauna of Wyoming, suggesting an early middle Tiffanian age. Diversity analyses using standardized samples and rank abundance curves suggest that the Tiffanian interval in Alberta fails to show a significant decline in mammalian species diversity as would be predicted by recent late Paleocene global cooling models.
ISBN
9780494455951
0494455950