Pit 91

Pit 91. La Brea Tar Pits. Did you know you are standing above a large underground oil field? This oil seeps to the surface as sticky asphalt. Plants and unwary animals have been getting trapped in this treacherous goo for thousands of years. Being stuck in the La Brea Tar Pits was a terrible way to die-but a great way to preserve fossils! , Pit 91: Active fossil dig , You're standing in front of an active fossil dig! We first dug into Pit 91 in 1915 and continue to excavate here in the summer. We've found fossils of extinct saber-toothed cats and other large animals. We've also found fossils of smaller animals and plants. Come inside and take a look! How old? , The oldest fossils from Pit 91 date back 44,000 years. The most recent fossils are 14,000 years old. , How deep? , We've dug 15 feet deep. We might find fossils up to five feet deeper. , Did you know? , We've even found the fossils of flies that fed on dead animals trapped in the Tar Pits. , Solving Ice Age Mysteries, Tiny fossils give us clues , Tiny fossils of plants, insects, and other small animals give us information that we can't get from large fossils. These microfossils tell us about L.A.'s climate and habitat and how they changed over the past 50,000 years. They can also help us understand changes that are happening now - and may happen in the future. , Fossils from Pit 91 and what this tells us, Rainbow trout bones: Today, rainbow trout live in year-round streams. Finding their fossils in Pit 91 tells us that streams once flowed here all year long. , Monterey cypress cones: Today Monterrey cypress trees live only where it is cool and rainy. Because they once lived here, winters then were probably colder and wetter. , Jaw of a fence lizard: Fence lizards are one of the many small animals that lived here up to 44,000 years ago. Unlike the saber-toothed cat and some of the other megafauna, most of these small animals survive today. , megafauna= mega or "big" plus fauna or "animal". , microfossil=a fossil or part of a fossil smaller than one-quarter inch. , Found here, In the past 100 years, we've dug more than 100 pits to locate fossils here in the park. This was the 91st pit we opened., Big bones raise big questions , The tar pits trapped large animals that lived in the L.A. basin from 55,000 to 11,000 years ago. Many of these species are now extinct. Ech fossil we find provides clues about life in L.A. in the prehistoric past. But one of the biggest mysteries still remains: Why did many of the largest animals we find here die out? , fossil=remains of an animal or plant preserved by natural causes. In the Tar Pits the fossils are preserved by asphalt. , We've found an incredible number of fossils at Pit 91, including: Saber-toothed Cats: 73 , Dire Wolves: 56 , Coyotes: 16 , Ancient Bison: 12 , Western Horse: 13 , Harlan's Ground Sloths: 6 , Giant Jaguars: 6 , Short-Faced Bears: 4 , Yesterday's Camels: 2 , American Mastodon: 1 ,