Biology ETDs
Publication Date
Summer 7-28-2026
Abstract
Fossil records are saturated with small mammals, and their ecological responses to environmental stressors represent both an understudied sensitive system and potential tracers from which to reconstruct and gauge past and present change. Chapter 1 ground-truths 3D dental ecomorphology, δ13C and δ15N stable isotopes, and dental microwear texture analysis in modern Texas rodents. Ecomorphology and isotopes provide congruent, complementary dietary information whereas microwear primarily reflects short-term precipitation rather than fine-scale diet. Chapter 2 examines Onychomys grasshopper mice using body size, stable isotopes, and dental ecomorphology at Hall’s Cave, Texas, demonstrating coordinated cross-proxy responses to extinction. Chapter 3 applies these methods to 10 rodent taxa over the Hall’s Cave record, revealing that climate mostly structured body size, while extinction compressed isotopic niche space, increased potential resource competition, and evinced rapid morphological adaptation. Together, these chapters show that multiproxy, multitaxon approaches can characterize ecological shifts associated with climate change and biodiversity loss.
Project Sponsors
National Science Foundation (DEB 1555525 and 1744223), American Society of Mammalogists, Paleontological Society, and Geological Society of America
Language
English
Keywords
Ecology, morphology, diet, climate change, biodiversity loss, extinction
Document Type
Dissertation
Degree Name
Biology
Level of Degree
Doctoral
Department Name
UNM Biology Department
First Committee Member (Chair)
Dr. Felisa A. Smith
Second Committee Member
Dr. Jason R. Moore
Third Committee Member
Dr. Rebecca C. Terry
Fourth Committee Member
Dr. Tara M. Smiley
Recommended Citation
Keller, Jonathan. "LARGE CHANGES FOR SMALL MAMMALS: USING MULTIPLE PROXIES TO RECONSTRUCT ECOLOGICAL RESPONSES TO LATE QUATERNARY CLIMATE CHANGE AND BIODIVERSITY LOSS." (2026). https://digitalrepository.unm.edu/biol_etds/671