Inferring diel activity pattern from bony orbit dimensions
how broadly can we apply generalizations about the way that morphology relates to function?
A few of the linear measurements I took on 429 skulls from 51 species of sciurids; Smith et al. 2018.
This project was a collaboration with Ken Angielczyk (Field Museum) to study the relationship between bony orbit dimensions and diel activity pattern (DAP) in sciurid rodents, with the eventual goal of using orbit dimensions to infer activity pattern in non-mammalian synapsids. We collaborated with Lars Schmitz (Claremont-McKenna) and Steve Wang (Swarthmore) to investigate the possibility of predicting DAP in sciurids using orbit measurements and other cranial dimensions, using a variety of quantitative methods, including phylogenetic flexible discriminant analysis, classification trees, and logistic regression. We found that although there are some interfering phylogenetic factors, nocturnal and non-nocturnal sciurids can be differentiated from one another with over 80% accuracy using all the methods we investigated. Our results indicate that these analyses offer several viable options for predicting DAP in the fossil record, but such analyses should be conducted in a phylogenetic context whenever possible.
PUBLICATIONS
Smith, S. M., Angielczyk, K.D., Schmitz, L., Wang, S.C. 2018. “Do bony orbit dimensions predict diel activity pattern in sciurid rodents?” The Anatomical Record 301: 1774–1787. doi: 10.1002/ar.23900