Tar & Bones

Paleontologists could hardly have devised a better specimen trap than one which existed perhaps a million years ago near what is now Rancho La Brea in Los Angeles, Calif. Liquid asphalt oozing up from the earth formed a sticky surface pool, covered by a few inches of water. Because this water was unpleasant to the taste, animals preferred to drink from waterholes or streams fed by melting mountain snow. But the Pleistocene climate was sometimes dry and water was scarce. Then big herbivores such as Asiatic camels, mammoths, bison and ground sloth ventured into the asphalt to slake their thirst, became hopelessly stuck. Their struggles attracted sabre-tooth tigers, lions, wolves and coyotes which in turn were trapped in the tar. Swooping to feast on these carcasses came eagles and huge vultures which sometimes got caught while fighting among themselves. Few years ago the bones of all these creatures began finding their way into museums.

Spanish settlers soon discovered that the pool was a menace to livestock. Riders watched constantly for trapped cattle and horses which could be rescued with the lasso. Even today careless jackrabbits get entangled as if on a huge flypaper.

Some 30 years ago contractors began to dig up the La Brea asphalt for road paving, found it too full of bones to be used. An alert University of California scientist noticed that the discolored skeletons were mostly of extinct creatures. Gradually a mass of fossils found its way into the museums of the U. S. and the world. Never before had paleontologists seen an entire system of life so well preserved in a single locality.

Chicago's Field Museum of Natural History got enough material to reconstruct a ground sloth, a sabre-tooth tiger, a primitive horse, an extinct bison. Last week these skeletons were put on view in a group depicting the recurring drama of the Ice Age. The sloth, mired, is being attacked by the tiger, which itself is caught by one hind foot. The bison sniffs dubiously at the pool's edge. Scenting danger, the horse wheels away as if to escape.

This file is automatically generated by a robot program, so reader's discretion is required.