Study of the Brain Anatomy of Three Extinct Marsupials: Thylacinus cynocephalus, Thylacoleo carnifex, and Silvabestius johnnilandi

Author

Francisco GarciaFollow

Publication Date

Fall 12-11-2024

Degree Level

B.S.

Program

Honors

First Advisor

Dr. Thomas E. Macrini

Second Advisor

Dr. Camille A. Langston

Document Type

Thesis

Abstract

Marsupials are pouched mammals that today are mainly found in Australasia and South America. Marsupials have proven to be quite intriguing to evolutionary biologists who note how some marsupials resemble placentals in anatomy due to convergent evolution, with both marsupials and placentals filling similar niches in their respective environments. As of today, studies interested in marsupial brain evolution have published descriptions of cranial endocasts for several species of marsupials, with the number of descriptions seeing a massive boost over the last 20 years with the arrival of CT imaging technology. However, no comprehensive study of brain evolution in marsupials has been published to date. By looking at the cranial endocast, a three-dimensional representation of the space within the endocranial cavity of the skull where the brain is housed, we can examine the surface anatomy of and study an extinct marsupial’s brain that we have an intact skull for. In this study, the digital cranial endocasts of the extinct marsupials Thylacinus cynocephalus, the marsupial wolf, Thylacoleo carnifex, the marsupial lion, and Silvabestius johnnilandi, the marsupial sheep are examined. I labeled brain anatomy on images of digital endocasts of these species with the purpose of comparing these endocasts with each other. The new data presented in this thesis will help provide a more complete picture of brain evolution in marsupials throughout time.

Recommended Citation

Garcia Francisco M. Study of the brain anatomy of three extinct marsupials: Thylacinus cynocephalus, Thylacoleo carnifex, and Silvabestius johnnilandi. Digital Commons at St. Mary’s University. 2024.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.