Rancho La Brea

The Rancho La Brea tar pits are the source of one of the richest deposits of Ice Age fossils in the world. As well as the large mammal fossils which the deposits are famous for, a wide diversity of both plant and animal species have been recovered from La Brea.

The fossils from La Brea were deposited during the Pleistocene, between 40,000 and 8,000 years ago. Rancho La Brea is situated on the Santa Monica Plain, in the north west part of the Los Angeles Basin in Southern California.

The tar pits represent one of many types of Lagerstätten, fossil deposits which are exceptional either in the quality of preservation or in the quantity of fossils. La Brea is an example of a concentration Lagerstätten, because it is noted for its large quantity of fossils. The tar pits formed concentration traps in which organisms became trapped and died. Other examples of concentration Lagerstätten include fissure fills, cave deposits and bone beds. Conservation Lagerstätten are those in which fossils are exceptionally preserved, for example the Burgess Shale and the Solnhofen Limestone. Although the soft parts of organisms were not preserved at La Brea, the bones do show very precise detail, and so can be very informative.

History

Geology

Original Environment

Entrapment

Preservation

Fossil Diversity

Current Work


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Rebecca Smith and Caroline Milner
Last Updated 25/01/01


Smilodon skeleton. Picture courtesy of Simon Powell, University of Bristol.
This picture is copyright. If you wish to use it, contact Liz Loeffler.