Wyoming Geological Association

44th Annual Field Conference Guidebook

1994

The Dinosaurs of Wyoming

Editor

GERALD E. NELSON

Casper, Wyoming June 16-20, 1994

TABLE OF CONTENTS

Dedication: Brent Breithaupt...ii

In Memoriam...iii

Greetings and Editor's Comments...v

List of WGA Officers and Field Conference Committee...viii

Wyoming Stratigraphic Chart...ix

GENERAL

Dinosaur Exhibits in Wyoming - Brent H. Breithaupt and Jerry Nelson...1

The Cottonwood Creek Dinosaur Trail - Kent Sundell, Ph.D...9

Paleontological Resource Management on Public Lands - Laurie J. Bryant, Ph.D...13

Wyoming's First Discovered Dinosaur - Brent H. Breithaupt...15

DINOSAUR MECHANICS

Dinosaur Tail Dynamics - Leslie Gertsch, Ph.D...25

DINOSAUR EXPLORATION

Ground Penetrating Radar Survey of Bone-Cabin Quarry - Stephen P. Gardiner and Louis H. Taylor...39

STRATIGRAPHY AND THE CRETACEOUS-TERTIARY BOUNDARY

The "Great Lignite," "Ceratops Beds," and Associated Lithostratigraphic Units at the K-T Boundary, Powder River Basin, Wyoming - Harold A. Boyd...61

The K-T Boundary at Sussex, Wyoming - Evidence for a Major Extinction Event at the End of the Age of Dinosaurs - Douglas J. Nichols and Janet L. Brown...85

DESCRIPTIONS OF WYOMING'S DINOSAURS AND REPTILES

Wyoming's Dinosaur Diversity - Brent H. Breithaupt...101

The Beginning of the Age of Dinosaurs in Wyoming - Spencer G. Lucas...105

Late Jurassic Dinosaur Localities in the Morrison Formation of Northeastern Wyoming - John R.Foster and James F. Martin...115

Dinosaurs of the Lance Formation in Eastern Wyoming - Kraig Derstler, Ph.D...127

Tyrannosaurus Sex - Peter L. Larson...147

Apatosaurus Yahnahpin: A preliminary Description of a New Species of Diplodocid from Late Jurassic Morrison Formation of Southern Wyoming - James Filla and Pat Redman...169

A Preliminary Description of Two New Marine Reptiles from the Upper Sundance Formation, Wyoming - Melissa Drake and William Wahl, Jr...189

DEDICATION

The 1994 Field Conference committee would like to dedicate this guidebook to Brent H. Breithaupt, curator of the Geological Museum at the University of Wyoming.

Brent Breithaupt was born in Milwaukee, Wisconsin, and received his Bachelor of Science degree in geology from the University of Wisconsin-Milwaukee in 1978. He received a Master of Science degree in geology from the University of Wyoming in 1981. Brent became curator of the Geological Museum at the University of Wyoming in 1981, a position he has held ever since. Brent has written more than 40 scientific papers on various aspects of the paleontology of Wyoming, and he has many more in various stages of preparation.

Brent is as close as we have to an "official" Wyoming state paleontologist. With boundless energy, he ranges across the state, delivering talks and slide shows about paleontology to every group that asks. He is enthusiastic, knowledgeable, and generous with his time and expertise. Thousands of school children visit the geology museum at the University of Wyoming each year; they all come away with an increased understanding of Wyoming's prehistoric life and an appreciation for our paleontological heritage.

Brent Breithaupt's generosity and enthusiastic approach to paleontology is not limited to his duties as curator of the University of Wyoming geology museum. He has been instrumental in helping the Tate Geological Museum at Casper College get started along the pathway to professionalism. He has advised us on scientific questions, helped us to identify fossils, lent us material from the University of Wyoming collections, and given moral support to our efforts.

Brent Breithaupt is an indefatigable leader and one-man cheering section for Wyoming's paleontological resources. It is appropriate, and a great honor for us, to dedicate this volume on Wyoming's Dinosaurs to Brent Breithaupt.

Jerry Nelson, Editor