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    • Diana Wright

      La Brea Tarpits

    • Susan Davis

      La Brea Tar Pits, Los Angeles

    • Lynda Taffi

      Tar pits around the world are unusual in accumulating more predators than prey. The reason for this is unknown, but one theory is that a large prey animal would die or become stuck in a tar pit, attracting predators across long distances. This predator trap would catch predators along with their prey. Another theory is that dire wolves and their prey may have been trapped during a hunt. Since modern wolves hunt in packs, each prey animal could take several wolves with it.

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    Rancho La Brea is the most famous, but two other asphalt pits have fossils in southern California: the Carpinteria Tar Pits in Carpinteria, Santa Barbara County and the McKittrick Tar Pits in McKittrick, in Kern County. Other asphalt deposits in Texas, Peru, Trinidad, Iran, Russia, Venezuela, and Poland also bear fossils.

    Smilodon. La Brea Tar Pits/ Page Museum 5801 Wilshire Boulevard Los Angeles, CA 90036 (323) 934-7243. The George C. Page Museum is dedicated to researching the tar pits and displaying specimens from the animals that died there. The La Brea Tar Pits are now a registered National Natural Landmark.

    Tar pits are composed of heavy oil fractions called asphaltum, which seeped from the earth as oil. In Hancock Park, crude oil seeps up along the 6th Street Fault from the Salt Lake Oil Field, which underlies much of the Fairfax District north of the park. The oil reaches the surface and forms pools at several locations in the park, becoming asphalt as the lighter fractions of the petroleum biodegrade or evaporate.

    The tar pits visible today are actually from human excavation. The lake pit was originally an asphalt mine. The other pits visible today were produced during the 1913–1915 excavations, when over 100 pits were excavated in search of large mammal bones. Various combinations of asphaltum and water have since filled in these holes.

    As the bones of the dead animals sink into the asphalt, it soaks into them, turning them a dark-brown or black color. Lighter fractions of petroleum evaporate from the asphalt, leaving a more solid substance, which holds the bones. Apart from the dramatic fossils of large mammals, the asphalt also preserves very small "microfossils": wood and plant remnants, rodent bones, insects, mollusks, dust, seeds, leaves, and even pollen grains

    The Portolá expedition, a group of Spanish explorers led by Gaspar de Portolá, made the first written record of the tar pits in 1769. Father Juan Crespí wrote, "While crossing the basin the scouts reported having seen some geysers of tar issuing from the ground like springs; it boils up molten, and the water runs to one side and the tar to the other. We christened them Los Volcanes de Brea [the Tar Volcanoes].

    Union Oil geologist W. W. Orcutt is credited with first recognizing fossilized prehistoric animal bones preserved in pools of asphalt on the Hancock Ranch in 1901. These would be the first of many fossils excavated from the La Brea Tar Pits.

    Methane gas escapes from the tar pits, causing bubbles that appear to boil. Asphalt and methane appear under surrounding buildings, and require special operations for removal to prevent weakening building foundations. In 2007, researchers from UC Riverside discovered that the bubbles were caused by hardy forms of bacteria embedded in the natural asphalt. After consuming petroleum, the bacteria release methane. Of the bacteria sampled so far, about 200 to 300 are previously unknown species

    Of more than a hundred pits, only Pit 91 is still regularly excavated by researchers, and can be seen at the Pit 91 viewing station, which is outside the museum, and free to enter. Currently, Pit 91 excavations have been put on hiatus so excavators can operate year-round on material from Project 23. Paleontologists supervise and direct the work of volunteers

    Contemporary excavations of the bones started in 1913–1915. In the 1940s and 1950s, public excitement was generated by the preparation of previously recovered dramatic large mammal bones. By the 1970s, research attention had shifted to smaller specimens, such as preserved insects and plant parts, including microfossils, such as pollen grains. These remains have contributed to an understanding of the Los Angeles basin during the glacial age.

    On February 18, 2009, George C. Page Museum formally announced the 2006 discovery of 16 fossil deposits which had been removed from the ground during the construction of an underground parking garage for the Los Angeles County Museum of Art next to the tar pits. Among the finds are remains of a saber-toothed cat, six dire wolves, bison, horses, a giant ground sloth, turtles, snails, clams, millipedes, fish, gophers, and an American lion.

    These fossils were packaged in tree boxes at the construction site and moved to a compound behind Pit 91, on Page museum property so that construction could continue. Twenty-three large accumulations of tar and specimens were taken to the Page Museum. These deposits are worked on under the name "Project 23". As work for the public transit Metro Purple Line is extended, museum researchers know more tar pits will be uncovered, for example near the intersection of Wilshire and Curson

    Brea is Spanish for "tar." The "tar" pits were used as a source of asphalt (for use as low-grade fuel and for waterproofing and insulation) by early settlers of the Los Angeles area. The original Rancho La Brea land grant stipulated that the tar pits be open to the public for the use of the local Pueblo. Initially, they mistook the bones in the pits for the remains of pronghorn antelope or cattle that had become mired.

    Only one human has ever been found, a partial skeleton of the La Brea Woman dated to approximately 10,000 calendar years (~9,000 radiocarbon years) BP, who was 17 to 25 years old at death,and found associated with remains of a domestic dog, and so was interpreted to have been ceremonially interred.

    Rancho La Brea is the most famous, but two other asphalt pits have fossils in southern California: the Carpinteria Tar Pits in Carpinteria, Santa Barbara County and the McKittrick Tar Pits in McKittrick, in Kern County. Other asphalt deposits in Texas, Peru, Trinidad, Iran, Russia, Venezuela, and Poland also bear fossils.

    Tar pits around the world are unusual in accumulating more predators than prey. The reason for this is unknown, but one theory is that a large prey animal would die or become stuck in a tar pit, attracting predators across long distances. This predator trap would catch predators along with their prey. Another theory is that dire wolves and their prey may have been trapped during a hunt. Since modern wolves hunt in packs, each prey animal could take several wolves with it.

    La Brea Tar Pits 1962. La Brea tar pits, containing one of the richest, best preserved, and best studied assemblages of Pleistocene vertebrates, including at least 59 species of mammal and over 135 species of bird. The tar pit fossils bear eloquent witness to life in southern California from 40,000 to 8,000 years ago; aside from vertebrates, they include plants, mollusks, and insects -- over 660 species of organisms in all.

    Smilodon californicus Smilodon, the most famous of the sabre-toothed cats, is the second most common fossil at La Brea. Literally hundreds of thousands of its bones have been found, representing thousands of individuals. It was first described by Professor John C. Merriam and his student Chester Stock in 1932. Today, it is the California state fossil. But Smilodon was not restricted to California; it ranged over much of North and South America.

    In today's ecosystems herbivores are much more abundant than carnivores. It is therefore curious that at La Brea about 90% of the mammal fossils found represent carnivores. Most of the bird fossils are also predators or scavengers, including vultures, condors, eagles, and giant, extinct, storklike birds known as teratorns. Why is this the case? If a pack of carnivorous mammals were to chase a lone prey animal into the tar pits, both predators and prey would become trapped.

    Scientists from the University of California at Berkeley, notably Professor John C. Merriam and his students, were among the first researchers to work on the La Brea fossils. Today, the George C. Page Museum of La Brea Discoveries, right next door to the tar pits themselves, displays huge numbers of La Brea fossils. The Page Museum is part of the Natural History Museum of Los Angeles County.

    Los Angeles was somewhat cooler and moister 40,000 years ago than it is today. Many of the plants and animals found in La Brea are identical or almost identical with species that still live in the area -- or that would be living in the area had Los Angeles not gotten in the way. Yet a number of the large animal species found at La Brea are no longer found in North America: native horses, camels, mammoths and mastodons, longhorned bison, and sabre-toothed cats.

    This fossil was originally described as the species Canis milleri, restudy has shown that it is a subspecies of C. lupus, the gray wolf. In the Pleistocene, gray wolves shared the region with C. dirus, the dire wolf. Gray wolves had the largest natural range of any mammal species except for Homo sapiens; at one time they were found in every habitat of the Northern Hemisphere except for deserts and the tropics.

    la Brea Tar Pits, Mastodons from Rancho La Brea tend to be smaller than those found at other localities. They are represented by at least 15 individuals including a baby from Project 23.

    El Pueblo de Nuestra Señora la Reina de los Ángeles was founded in 1781. The citizens of the pueblo used asphalt from local seeps to waterproof the roofs of their houses and as a fuel.

    1913-1915 Excavations In 1913, the Hancock family gave the newly established Los Angeles County Museum sole right to excavate fossils from the tar pits for two years. Led by L. E. Wyman, excavators earned 3.50 a day, decent wages for 1913.