Date of Award


Document Type


Degree Name

Master of Science in Biology



First Advisor

Sumida, Stuart

Second Advisor

Metcalf, Anthony

Third Advisor

Polcyn, David, and Middleton, Kevin


Basal synapsids comprise one of the best represented groups of early tetrapods and demonstrate a classic example of a macroevolutionary transition. The basal synapsid fossil record is of significant interest to paleontolists because it presents an excellent opportunity for studying the evolution of vertebrate morphology. In the present study, neural spine osteohistology is further examined across a broad range of basal synapsid genera with hyperlongate neural spines. Due to the limited availability of specimens and the comparative approach required for destructive analysis, the present study is divided into two major comparative investigations: analysis of hyperlongate neural spine in (1) Spenacodontidae and (2) Edaphosauridae.