Graduation Semester and Year
Summer 2024
Language
English
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Biology
Department
Biology
First Advisor
Eric N. Smith
Second Advisor
Esther Betran
Third Advisor
Todd A. Castoe
Fourth Advisor
Luke O. Frishkoff
Fifth Advisor
Matthew K. Fujita
Abstract
The popularization of high-resolution computed tomography(HRCT) has produced a revolution in the field of comparative anatomy. This technology allows us to reach a level of morphological detail in our observations that has never been possible previously. Now we can perform digital dissections isolating structures of interest such as individual bones, soft tissue organs, and even generate 3D models of body cavities (endocasts) such as the braincase and inner ear. Encompassed with the progress of the HRCT, 3D geometric morphometrics have emerged as a common tool to address morphological questions in a statistical context that outperforms the traditional 2D geometric morphometrics. In chapter 1 we provide a detailed description and illustrations, bone by bone, of the skull and hyoid of Echinosaura horrida. We discussed its intraspecific variation by comparing high-resolution computed tomography data from two specimens and the variation within the genus by including previously published data from Echinosaura fischerorum. Novel characters with relevance for the classification within Echinosaura and Gymnophthalmoidea were identified. In chapter 2, we describe qualitatively and quantitatively (using 3D morphometrics) the anatomy of the inner ear of amphisbaenians demonstrating great morphological diversity in this clade. Results from the morphological analyses also allow us to describe 11 new phylogenetic characters including some that help defining amphisbaenians, including the globular vestibule, semicircular canals arranged in a circular trajectory, and a reduced lagenar recess relative to the oval fenestra size. In chapter 3, we perform the most comprehensive study of the lacertoidean inner ear using a high-density geometric morphometrics approach. We found that the main sources of variation are associated with the overall compactness of the inner ear. There is a low level of modularity and the inner ear mostly fits a Brownian evolution model.
Keywords
Gymnophthalmidae, comparative morphology, CT-Scanning, endocast
Disciplines
Biodiversity | Evolution | Integrative Biology | Zoology
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Hernandez, Cristian, "THE MORPHOLOGICAL EVOLUTION OF THE INNER EAR IN LACERTOIDEA (SQUAMATA)" (2024). Biology Dissertations. 142.
https://mavmatrix.uta.edu/biology_dissertations/142