One hundred fifty million years ago North America was home to magnificent dinosaurs, winged pterosaurs, and the swimming and paddling reptiles of the midcontinental sea. Now, when camping alone in the deserts of the American West after long hours of excavation, I can almost hear the grunts and groans of these ghosts of the Jurassic. I see a herd of Diplodocus jostling for position at a watering hole or sweeping across a barren landscape in quest of food along the river just over the horizon.

Their bones are all that remain. My hands gently expose them one by one. Each is a reminder of the history of our continent--a world so remote and strange that even poets can scarcely portray the Age of Dinosaurs. But with each bone, our link with this past becomes firmer and the era all the more spectacular.

One hundred fifty million years ago a dinosaur died in what is now central New Mexico. Attacked by scavengers and decomposers, the remains were finally buried beneath the sands of a capricious river. That particular dinosaur now lives again in a new way: it has a name, and it is the subject of an exciting episode in the realm of paleontology.

In the pages that follow, I hope to convey the rich story of how Seismosaurus hallorum--one of the biggest of all dinosaurs yet discovered--was reborn as the cherished fossil "Sam." The paleontological portion of the tale begins on a hot wind-swept mesa in 1979. It is a story more of people than bones, more of ideas than facts. And it is an adventure that has dominated my life for nearly a decade.

To those people who have shared in the toil, frustrations, and joys of discovery I am deeply indebted, for they have contributed in many ways to what has come to be called the Seismosaurus Project. Wilson and Peggy Bechtel, working on grants administered by the Southwest Paleontology Foundation, have spent more time on site than anyone else, myself included; since 1988 they have assumed responsibility for the day-to-day management of the excavation, supervision of volunteers, and coordination with government agencies. But for their dedication and persistence this project would have succumbed to financial and organizational difficulties long ago.

All of us involved in the project are indebted to the original discoverers, Arthur Loy and Jan Cummings, who protected the exposed bones and who, with Frank Walker and Bill Norlander, brought them to our attention in 1985.

Among the dozens of volunteers who assisted with the excavation, Kirk Bentson, Bob Webster, and Charles Knapp deserve special recognition for hundreds of hours of service. Additional volunteers include Bertrand and Beatrice Block, Lynett Gillette, Howie Green, Charles Harris, Pam Kuster, Stan Lundy, Joe McDowell, Barry Moore, Matt Mygatt, Lyle Newman, Carol Orr, Hilde Schwartz, Ed Springer, Bob and Linda Strong, Frank Walsh, Woody Weld, Mahlon Wilson, and Gary Yohler.

From Los Alamos National Laboratory (Los Alamos, New Mexico), Roland Hagan and George Matlack were the principal organizers for remote sensing experiments on site and for research in the chemistry of fossil bone. To them I owe a great deal, for they have guided me into a world of technology that is a paleontologist's dream. Many other scientists from Los Alamos contributed in numerous ways. Among them are Harold Bowen, Lawrence Gurley, Rod Hardy, Bill Johnson, Kim Manly, David Mann, Randy Mynard, Carrie Neeper, Don Neeper, John Phillips, Dale Spall, Don VanEtten, and Phil Vergamini.

Two scientists from Sandia National Laboratory (Albuquerque, New Mexico), Cliff Kinnebrew and Wayne Cooke, repeatedly visited the quarry to test their ground-penetrating radar. A team from Oak Ridge National Laboratory (Oak Ridge, Tennessee) consisting of Alan Witten, Joe Sypniewski, and Chris King (dubbed the Seismosaurus Tour) visited the site several times and made important contributions in applications of acoustic diffraction tomography.

Several individuals employed by the U.S. Bureau of Land Management in New Mexico--Al Abbey, Angie Burger, Harry DeLong, Pat Hester, Mike O'Neill, and Dennis Umshler--deftly managed our permits and kept the project within the limits required by law. Especially during early stages of the project, taphonomist Hilde Schwartz contributed to understanding the geological setting. John McIntosh, James H. Madsen, Jr., and Wann Langston helped with identification and advice on sauropod dinosaurs.

Institutional support came from many places: the New Mexico Museum of Natural History, the Division of State History of the State of Utah, Brigham Young University, Los Alamos National Laboratory, Sandia National Laboratory, Oak Ridge National Laboratory, the Smithsonian Institution, the Ghost Ranch Conference Center, the U.S. Bureau of Land Management, and the New Mexico Friends of Paleontology.

Major funding for the project came from the Smithsonian Institution, the National Geographic Society, the National Science Foundation, and the Martin Marietta Foundation. Additional financial support and in-kind contributions from Ann and Gordon Getty, Bertrand and Beatrice Block, Gary Yohler and Pam Custer, Randolph Township Schools (New Jersey), Kirk Bentson, Chuck Harris, Adrian Madera, Frank Beall, and the BTM Wrecker Service and smaller donations from many more contributed to the success of the project.

For friendship and counsel, I am indebted to Wilson Bechtel, Peggy Bechtel, David Thomas, Edwin H. Colbert, Margaret Colbert, Jennifer Gillette, Lynett Gillette, my parents--Dean and Julia Gillette--and Janet Whitmore. Ed Lugenbeel, Laura Wood, and Anne McCoy at Columbia University Press guided me through the process of publication. Freelance manuscript editor Connie Barlow expertly turned my drafts into consistent and manageable text, and to her I am deeply indebted. I thank David Weishampel and Edwin H. Colbert for critical reviews, which greatly improved the text.

Working with dinosaur illustrator par excellence Mark Hallett has been a great pleasure, for he has the uncanny ability to turn words into images that are real and dramatic. All drawings and paintings in this book are Hallett's. Except as noted, all photographs are mine, copyrighted by the Southwest Paleontology Foundation, Inc.

Finally I am grateful to Lynett Gillette and Jennifer Gillette for their encouragement and unfailing support, and to my friend Paul Bowles, now age eleven, whose theories on dinosaur paleobiology challenged me in more ways than he may ever know.

I dedicate this book to all those who have helped in the Seismosaurus Project, and in particular to Paul Bowles and Wilson and Peggy Bechtel.