Bio 482 Aranoff

Research Description

The Cretaceous-Paleogene mass extinction catalyzed the evolutionary rise of the mammal lineage. However, the ecological trends of the resulting biotic recovery are not very well known. To better understand this pivotal evolutionary radiation, mammal paleontologists study fossil teeth, which are quite resistant to the wear caused by long-term environmental stress. These scientists examine teeth to learn more about the ecomorphological characteristics of species that walked the Earth millions of years ago. Generally, ecomorphology describes the association between an organism’s morphological traits and its ecological niche. For instance, researchers have previously associated differences in tooth shape with variations in the diets of euarchontan mammals. My project similarly compares disparities in tooth shape to determine organisms’ dietary preferences.

I performed a quantitative comparison of extinct and extant mammal teeth to examine the ecomorphological relationship between tooth morphology and dietary preference in ancient mammals. First, I compiled sample teeth for both groups. My extinct data set included the Archaic Ungulates, an early Paleocene eutherian group, while my extant data set varied across mammal taxa. The extant mammal sample included five dietary categories: carnivores, herbivores, frugivores, duraphages, and insectivores. My goal was to connect the dental structures and dietary preferences of the extant mammals to the ecomorphology, i.e. the tooth shape and diets, of the extinct Archaic Ungulates. I performed ecometric analyses, including Relief Index and Orientation Patch Count (OPC), in order to achieve my objective.

Paleontologists strive to understand both the organisms that inhabited ancient times and the ecology of prehistoric communities. This project will help increase our knowledge of the ecological roles of certain mammals that lived during the early Cenozoic Era (right after the K-T) and therefore the environments in which these organisms lived.