Balcones Research Center, University of Texas at Austin, © 1997 by Phyllis Janik.

Scientists examining the head of Chasmosaurusmariscalensis hone their understanding of nature by comparing it against observations of the world. Clockwise from upper left: Prof. Paul Sereno, Univ. of Chicago; assistant Cathy Forster, Univ. of Chicago; students Hilary Tindle and Tom Evans, who discovered the skull in the field in March 1991 in Big Bend National Park, Texas.