All News

Paleontologists studying La Brea Tar Pits fossils reveal the extinction of California’s megafauna was likely linked to ancient wildfires, human activity

Paleontologists have made a significant discovery at La Brea Tar Pits, revealing that the mass extinction of Pleistocene-era large mammals was likely influenced by human-ignited wildfires, exacerbated by rapid warming and environmental stress. Researchers conducted radiocarbon dating on 172 specimens across the Rancho La Brea Site, where asphalt seeps have preserved bones of various megafaunal species over the last 50,000 years.

The results suggest that the mass extinction of most mega-mammal species occurred around 12.9 thousand years ago, coinciding with a shift in regional ecology characterized by altered flora and increased human activity. This research highlights a transition from a postglacial megafaunal woodland supporting large mammals, to a human-impacted chaparral ecosystem of semi-arid land.

Severe climate change continues to jeopardize our ecosystems today. With this increased urgency, Weiss/Manfredi’s master plan for La Brea Tar Pits creates new opportunities for preservation, sustainability, education, and research.

Learn more about the paleontologists’ findings and the ecology of the ancient Pleistocene era at

La Brea Tar Pits and Museum Master Plan
The renovation and expansion is conceived as a contemporary Wunderkammer, a treasure chest of stunning fossils and artifacts, from large to microscopic.
Museum of the Earth
Set within the hillside and adjacent to the existing research facility, the museum is organized into two parallel and interconnected buildings.
Hunter's Point South Waterfront Park
Hunter’s Point South Waterfront Park transforms 30 acres of post-industrial waterfront into a program-rich public space that simultaneously acts as a protective perimeter for the neighboring residential community.
Seattle Art Museum: Olympic Sculpture Park
A continuous constructed landscape for art, the uninterrupted Z-shaped "green" platform rises over the existing infrastructure to reconnect the urban core to the revitalized Seattle waterfront.