How To Look At Dinosaur Tracks

["Richard W. Travsky" <rtravsky@uwyo.edu>]

http://www.sciencedaily.com/releases/2007/04/070430102016.htm

A new study appearing in the May issue of The Journal of Geology provides 
fascinating insight into the factors geologists must account for when 
examining dinosaur tracks. The authors studied a range of larger tracks 
from the family of dinosaurs that includes the T. Rex and the tridactyl, 
and provide a guide for interpreting the effects of many different types 
of erosion on these invaluable impressions.

"Well-preserved vertebrate tracks in the rock record can be an invaluable 
source of information about foot morphology, soft tissue distribution, and 
skin texture," write Jesper Miln (Geological Institute, University of 
Copenhagen) and David B. Loope (Department of Geosciences, University of 
Nebraska, Lincoln). "However, in most instances, the tracks are less than 
perfectly preserved, and sometimes they can be barely recognizable as 
tracks at all."

With this in mind, Miln and Loope sought to describe and categorize 
different levels of preservation.
...
For example, estimating foot length from tracks can be inaccurate without 
these considerations -- the more erosion that has occurred, the larger the 
apparent dimensions of the track. Applications of this apparently larger 
foot size derived from an undertrack may lead to calculations of higher 
estimated hip length, and, as the authors point out, may also lead to 
slower speed estimates.

Reference: Jesper Miln and David B. Loope, "Preservation and Erosion of 
Theropod Tracks in Eolian Deposits: Examples from the Middle Jurassic 
Entrada Sandstone, Utah, U.S.A." The Journal of Geology: 115, p. 375-386.