9 Undergraduate Research (Posters)

Thursday, 7 April 2022
8:00 AM - 12:00 PM
Junior Ballroom B

A MORPHOLOGICAL ANALYSIS OF WOLF-LIKE CANIDS, AND A LOOK INTO AUGUSTANA'S DIRE WOLVES FROM THE LA BREA TAR PITS, LOS ANGELES, COUNTY, CA

Paper number: 9-54
Program: Theme Sessions
Time: 8:00 AM – 12:00 PM

Authors

  • Irysa Boyer Presenting Author
    Augustana College, Rock Island, IL

Abstract

During the Pleistocene, Aenocyon dirus, dire wolf, was a prominent member of the terrestrial mammal megafauna. A. dirus went extinct during the Late Pleistocene/Early Holocene Epoch. Today, this taxon is well-known from the fossils of the La Brea Tar Pits lagerstatte in, Los Angeles County, CA. At the La Brea site, A. dirus shared an ecosystem with two other wolf-like canids: the gray wolf and coyote. Due to their ecological and morphological similarities, it has long been believed that dire wolves were sister taxa to these other two canid groups. Recent phylogenetic research by Perri et al. (2021), however, has provided an alternative hypothesis — dire wolves are more genetically similar to African jackals (black-backed and side-stripped jackal) than to either gray wolves or coyotes. If this is true, then recent canid phylogenies will need to be reorganized.

Through this research, I aim to provide further support to the Perri et al. (2021) interpretations by determining whether morphological data supports the genetic link between dire wolves and African jackals. To do this, I utilized landmark analysis, high-resolution 2D imagery, and 3D photogrammetry to quantify the cranium and mandible morphologies of well-preserved skull specimens belonging to each of these four canid groups (dire wolves, gray wolves, coyotes, and African jackals). Specimens used were from Museum of the North, University of Alaska, Fairbanks; Buffalo Bill Center of the West, Cody, WY; Yale Peabody Museum, New Haven, CT; Raymond M. Alf Museum of Paleontology, Claremont, CA; Field Museum, Chicago, IL; Augustana College, Rock Island, IL; and from my own personal IL collection. Comparisons of measurements using bivariate and multivariate analytical methods are ongoing but seem to point to complex relationships among these canid groups that may be the result of: phylogeny, ontogeny, or evolutionary change (among fossil and recent taxa belonging to the same species). In early multivariate analyses using ordination, preliminary results show dissimilarity between dire wolf morphology and two canids: coyotes and gray wolves. Further analyses should aid in the understanding of whether relationships between dire wolf and the African jackals and between gray wolf and coyote are the result of genetic or convergent evolution.

Geological Society of America Abstracts with Programs. Vol. 54, No. 4

doi: 10.1130/abs/2022NC-375036

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