North-Central Section–40th Annual Meeting (20–21 April 2006)

Paper No. 30
Presentation Time: 8:00 AM-12:00 PM

USING VON EBNER LINES TO ASSES TOOTH REPLACEMENT RATES IN DEINONYCHUS


BERG, Holly, Geoscience, University of Iowa, 121 Trowbridge Hall, Iowa City, IA 52242 and MAKOVICKY, Peter, Geology, Field Museum of Natural History, 1400 S Lake Shore Drive, Chicago, IL 60605, holly-berg@uiowa.edu

Living amniotes deposit dentine daily, and the same was true for extinct dinosaurs. These layers of dentine can be analyzed in fossil archosaurs by observing incremental von Ebner lines, which are tens of micrometers in width. Von Ebner lines can be used to interpret tooth replacement rates and correlations between dentine growth and ontogeny. Current research utilizing the teeth of the Cretaceous dromaeosaurid theropod Deinonychus supports previous results with lower sample sizes. Analyses show that there was an increase in line width through ontogeny and that teeth formation decreases as an individual's size increases.