Book Offers Overview Of Cave Paleontology

Schubert, a graduate student in the environmental dynamics program, likes to study the bones and other objects found in caves. Those finds comprise enough of the record of Ice Age vertebrates to merit a book on the subject.

"Ice Age Cave Faunas of North America," published recently by Indiana University Press describes the manner and instances in which caves have relinquished the remains of tapirs, sloths, mammoths, lions and numerous rodent species that once roamed North America. Caves provide a particularly good environment for the preservation of diverse evidence of past life, including bones, teeth, skin, dung, ligaments, hair and feathers of extinct species.

"Unlike the surface, caves often maintain a stable environment for long periods of time," Schubert said. "They provide the bulk of the record on a lot of extinct animals." Protected from the elements in a tomb-like setting, fossils from caves offer important evidence of the vertebrate past.

Although caves can provide a vivid record of the past, cave paleontology remains a sparse specialty among researchers. To begin with, the study of Ice Age vertebrates narrows the field; adding caves to the mixture narrows it further.

"A bone one mile back in a cave may take half a day to reach," Schubert said. "That filters out a lot of people."

In fact, many important fossil finds are made by recreational cavers, who bring the remains to the attention of scientists. Schubert hopes that getting the word out about the importance of such findings to the Ice Age record will increase awareness among caving enthusiasts as well as other researchers.

"It provides a message to them about another aspect of caves that needs to be preserved," he said.

The book, co-edited by geology professor Jim I. Mead of Northern Arizona University and Russell W. Graham of the Denver Museum of Nature and Science, contains essays that range from an overview of the significance of cave fossils to studies of specific animal species and fossil locations.

In the essays, various researchers describe how they can reconstruct evolutionary patterns of organisms, climate changes and past ecosystems from cave remains. The Ice Age saw dramatic climatic changes and continental ice sheets that advanced and retreated several times. The last glacial retreat occurred between 15,000 and 10,000 years ago.

"Coinciding with this event we see the extinction of many species of large mammals, the reorganization of biological communities, and the dispersal of humans into the Americas," Schubert said.

Schubert wrote one chapter that reviews cave paleontology in the Ozarks, describes fossil vertebrates from a central Missouri cave that range in age from 12,000 to 10,000 years old, and reconstructs what the environment may have been like in this area during this dynamic period. Schubert also co-wrote a chapter on cave remains found at the Grand Canyon in Arizona, where findings included animals not previously known to have inhabited the area, like the short-horned lizard, ring-necked snake, sagebrush vole, ground squirrel and an extinct species called a shrubox. The fossil record they found dates back about 46,000 years.