La Brea Apr 2026

Beyond the charismatic megafauna, the tar pits have profoundly reshaped scientific understanding of extinction. The fossils at La Brea are so numerous and well-dated that they allow researchers to track changes in species populations over time. By comparing the fossil record from different asphalt deposits that span thousands of years, scientists have been able to rule out a single, catastrophic event, like a comet impact, as the sole cause of the Late Pleistocene extinction. Instead, the evidence from La Brea points to a perfect storm of factors: a rapidly warming climate at the end of the Ice Age, which drastically altered the plant life herbivores depended on, combined with the arrival of a new, highly efficient predator—humans. The Clovis people, ancestors of Native Americans, coexisted with these animals for a few thousand years, and the added hunting pressure likely pushed already-stressed populations over the edge.

Perhaps the most exciting aspect of the La Brea Tar Pits is that it is not a fossil story that ended long ago; it is a story that continues to unfold today. The site remains an active paleontological dig. When the Los Angeles County Museum of Art expanded its underground parking garage in 2006, construction crews uncovered a new fossil deposit, named Project 23, which contained over 700 distinct fossil deposits, including the nearly complete skeleton of a mammoth. Furthermore, the asphalt seeps are still active, trapping insects, birds, and small animals, reminding visitors that the process of fossilization is not just a chapter in the past but an ongoing feature of the landscape. Researchers are now using cutting-edge techniques like gas chromatography and radiocarbon dating to extract ancient DNA and analyze climate data trapped within the asphalt itself. La Brea

The story of the tar pits begins with the geology of the Los Angeles Basin. For tens of thousands of years, crude oil has seeped upward from underground reservoirs through fissures in the Earth’s crust. As the lighter components of the oil evaporate, a thick, sticky, black asphalt residue remains, creating a natural trap. During the Pleistocene epoch (the Ice Age), these asphalt seeps were often covered by layers of dust, leaves, or water, making them invisible to unsuspecting animals. A herbivore, such as a bison or a horse, wandering to a water source for a drink, could easily wander into the slick, sticky asphalt and become hopelessly mired. Its struggles would attract predators—dire wolves, saber-toothed cats, or American lions—who would then become trapped themselves in a deadly attempt to scavenge an easy meal. This recurring cycle of entrapment is why the La Brea pits are so incredibly rich in fossilized remains of carnivores. Beyond the charismatic megafauna, the tar pits have