Tar traps in the city

21. La Brea--the enormity of bones, the presence/absence of extinct land roaming mammoths in a human-scaled urban environment--A rouse of wonder, respect, and subtle sadness.

These black pit pools of asphalt, tar
or "brea" have been both ending and preserving the asphaltum-brown bones of various creatures for at least 38,000 years. The pits and park share common grounds with the Los Angeles County Museum of Art as well as the Page Museum.

Fiberglass mammoths and sloths are built to scale and settle about the grass and tar-scape. Fenced off pit pools, active excavation pits, exhausted pits, a pleistocence plant garden, a storage lot of excavated tar crates, and a small tar stream.

The Insides of the Page hold recovered remains, artist murals, informative time-lines, and reconstructed dioramas.

Treasures of the Tar Pits by Mark Hallet

The story of the tar

Faults and breaks in the sediment of the Los Angeles basin allowed deep dwelling oil deposits to rise and gather on the surface. The tar pools were likely covered with dust or debris, leaves and sticks. Animals, large and small could easily become trapped in just a few inches of tar in upon passing through the basin. These struggling animals attracted carnivorous species of many varieties, which themselves became trapped in the tar, attracting still more meat eaters and scavengers. It is this interminable system of trapping and feeding, death and struggle that has made the la Brea collection most plentiful in carnivorous species. The dire wolf is the most abundant specimen of all the discoveries, followed by the saber tooth and coyote. In fact, 90 % of animals found at la Brea are carnivorous creatures. An article by John Harris from Rancho La Brea--Death Trap and Treasure Trove puts it: "For every large herbivore in the collections there is a saber tooth, a coyote, and four dire wolves."

So, in the late 1800s the pits became a mining operation. The tar was utilized as fuel, as a preservative for pipes and rail ties, for roofing, as a sealant mortar for stone streets and walkways in the city. In 1875, a geologist by the name Denton visited the pits and found a saber cat's 11-inch tooth in the tar. The first major excavation operation began in 1909 and a collection of specimens began which later became the Natural History Museum of Los Angeles County. In the early excavations, the bones were removed from the tar and soaked in tubs of kerosene on the site then carted over to the museum. In the following years, more precise and elaborate excavation methods have been implemented and in 1977 the Page Museum and Hancock Park came into existence

Today, and even in the early 1900s, the fossils of La Brea have been recognized as one of the most important fossil collections in the world. The La Brea collection addresses the diversity of life and the climactic changes of California before, during, and after humans set their feet in North America.

All in all, more than 600 species have been documented to date (totaling well over 1 million bones). 58 species of mammal, 138 species of birds, 6 species of amphibians, 3 species of fish, 56 mollusk species, 168 kinds of arthropods, and many plant, tree and pollen remains. (A more comprehensive list sits at the foot of this blogpost)

Shasta ground sloth:
the smaller of the 2 sloth species found at La Brea
most common in the desert southwest

Harlan's Ground Sloth
stood over six feet tall
weighed in around 1500 lbs
probably ate grasses and trees.

The antique Bison:
larger than the modern bison
at least 150 found at La Brea,
still smaller than the long-horned bison(also found in La Brea),
the long horn's horn-span measured more than 7.2 feet

columbian mammoth:
most common mammoth of North America during the ice age
this one was likely 15,000 pounds and stood 12 feet tall.
35 found in La Brea
most were young males

lived most recently of the elephant related mammals
smaller than the mammoths

extinct camel:
most common camel at la brea
at least 36 individuals found
likely had a single hump

california sabertooth:
used forelimbs to pull down its prey then stabbed into the unprotected softer side
probably ambushed larger and slower animals like sloths, small mastodons, and mammoths

dire wolf
most common La Brea mammal (16,000 have been found thus far)
trapped in tar while pursuing trapped animals
similar to modern timberwolf
hunted in packs of 3 to 20
ate mostly small mammals but could bring down a bison or a camel

short faced bear:
larger than any present day American bears
a foot taller than the grizzly and twice its weight
a massive skull, short snout, and long legs

American lion:
larger than African lion & California saber
probably the most formidable predator of its time
around 100 recovered from La Brea

The Page had a viewing vista to a laboratory like fossil cleaning area

For the complete list of found specimens from the pits at la brea: