Excavations at the site of richest collection of Ice Age fossils to resume
The LA Brea Tar Pits are a collection of tar pits in urban Los Angeles which contain the richest and most diverse collection of Ice Age fossils on record. Last year, the George C. Page Museum celebrated a century of excavations at the pits. However, excavations are far from over and despite more than 5.5 million bones being extracted from the site, researchers believe that another century of research may not be enough to recover everything the tar pits have to offer. Now, for the first time in twenty years, two excavation pits are opening to the public, allowing onlookers to observe scientists dig for prehistoric fossils from a pool of naturally occurring asphalt.
Digs over the years have unearthed bones of more than 600 species of animals and plants, including mammoths, mastodons, saber-toothed cats, dire wolves, jaguars, giant ground sloth, and many other Ice Age animals that became trapped in ponds of sticky asphalt that seeped up through the ground in an area now known as Rancho La Brea, preserving the remains for thousands of years.
Saber-toothed cats are among the many carnivores found in La Brea's deposits. Credit: Natural History Museum
The asphalt would form a deposit thick enough to trap animals, and the surface would be covered with layers of water, dust, or leaves. Unsuspecting animals would wander in, become trapped, and eventually die. Predators would then enter to eat the trapped animals and also become stuck, leading to a massively diverse range of species found in the pits.
Apart from the dramatic fossils of large mammals, the asphalt has also preserved numerous insects, rodents, plants and even minute pollen grains, which are shaping scientists’ views of life in the region 11,000 to 50,000 years ago.
In the storage room of the George C. Page Museum lie floor-to-ceiling shelves of crates housing bones that need to be cleaned, identified or labelled. The museum estimates it has over 100,000 specimens still to catalogue and another million to scrub.
Nevertheless, despite a century of digging, scientists still can't agree on how the Ice Age animals became extinct. Some believe that the prehistoric predators may have competed with humans for similar prey. However, dental studies of saber-toothed cats and other carnivores suggest they were flourishing before they became extinct. Perhaps after another century of digging, the tar pits will reveal the rest of their mysteries.
Featured image: The LA tar pits with a reconstructed image of a mammoth trapped in the tar.