Publication Date
2024
Document Type
Dissertation/Thesis
First Advisor
Naples, Virginia L.
Degree Name
M.S. (Master of Science)
Legacy Department
Department of Biological Sciences
Abstract
The late Eocene and Oligocene is traditionally seen as a time of great climactic shift, with open habitats beginning to appear and forests receding. This time period saw both the diversification and subsequent extinction of North American nimravids. The causes of the extinction of this early sabertooth group in the Arikareean remain unclear. One possibility for their decline is that nimravids were competitively disadvantaged in open habitats relative to contemporary, possibly more cursorial caniform predators. Here I analyze and compare the hunting styles of Eocene and Oligocene predators in correlation with their ecological implications via discriminant function analysis of the shape of the elbow joint. The data show that the early Oligocene saw a decrease in large cursorial predators and an increase in ambush predators, primarily due to the diversification of the nimravids. An increase in the proportion of cursorial hunting predators only occurred in the Arikareean. My results indicate that nimravid elbow joint morphology, and therefore their inferred hunting styles, were very similar to that of contemporary canids. From this I hypothesize that it is unlikely that nimravids were disadvantaged in hunting compared to canids. However, it is possible there was a substantial enough gap between amphicyonid and nimravid hunting styles to suggest a competitive advantage for the former in the Arikareean. Ultimately, nimravid elbow morphology and diversification appear to indicate that ambush hunting was favored in the early Oligocene, although some more cursorial niches appeared as the Oligocene progressed.
Recommended Citation
Castellanos, Miguel Andres, "Hunting Types in North American Eocene and Oligocene Carnivores and Implications for Nimravid Extinction" (2024). Graduate Research Theses & Dissertations. 7875.
https://huskiecommons.lib.niu.edu/allgraduate-thesesdissertations/7875
Extent
50 pages
Language
en
Publisher
Northern Illinois University
Rights Statement
In Copyright
Rights Statement 2
NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.
Media Type
Text
