The La Brea Tar Pits are a group of natural asphalt pits in the Miracle Mile neighborhood of Los Angeles. Over many centuries, animals have been trapped in the sticky, viscous tar and their bones preserved for millennia. These tar pits are one of the world's most famous fossil localities, and over 3.5 million fossils have been found right here in LA’s stickiest museum!
The La Brea Tar Pits were formed over 50,000 years ago when crude oil seeped to the surface through fissures in the Earth's crust. Over a long period of time, the lighter fraction of the oil evaporated and left behind the heavy tar (or asphalt) in sticky pools.
Animals of all kinds were attracted to these tar pits by water and any plants that grew nearby. When they stepped in the tar, they would get stuck and slowly die — their bodies would be preserved in the tar and, over time, their bones would fossilize.
The La Brea Tar Pits have yielded fossils of over 650 species of animals, including mammals, birds, reptiles, amphibians, and fish. They are an important scientific site and provide scientists with a unique window into the past, helping us to understand the life and environment of Ice Age California.
That all being said, here are the mammals whose fossils have been found sunken in the gooey black tar of the La Brea Tar Pits!
Types of fossils found in the Los Angeles tar pits
Antelopes & deer
The tar pits have fossils from animals dating as far back as 50,000 years into California’s past — some of which are extinct and some who aren’t.
Familiar creatures like the pronghorn (Antilocapra americana), the mule deer (Odocoileus cf. O. hemionus) and the red deer (Cervus cf. C. elaphus) were found trapped in the pits, but their descendants are still roaming the hills and mountains freely today! The only species of this group that is no longer in existence today is the dwarf pronghorn (Capromeryx minor), a small, slender antelope-like animal which went extinct around 11,000 years ago.
Bats
Two bats found in the pits that you’re likely to see today are the Hoary bat (Lasiurus cinereus) and the Pallid bat (Antrozous pallidus), both of which are often seen around California’s oases and state parks.
Bears
There are just three species of bear in the La Brea Tar Pits, but their presence in the gooey fossil record helps biologists and paleontologists understand what the food chain 50,000 years ago looked like and how it differed from today’s.
It shows, for example, that the now-extinct giant short-faced bear (Arctodus simus) once roamed through Southern California before fading from existence at the end of the Ice Age 12,000 years ago. For nearly 300,000 years, this cuddly giant was one of the largest bears around and certainly the largest carnivore on the continent!
Also present in the pits are remains from the grizzly bear (Ursus arctos horribilis) and the black bear (Ursus americanus), both of which are still around today!
Cats
Did you know that California was once home to lions, tigers and bears? Oh my!
(Well, just two of those things, really).
But seriously, sunny SoCal was a predator’s paradise back in the Pleistocene era around 12,000 years ago. Large cats roamed the plains hunting bison, antelopes, birds and more while avoiding the much larger mastodons and mammoths who could crush them underfoot.
And while many of them succeeded, a few unlucky kitties ended up in a tar pit and were preserved for thousands of years.
These cats included the now-extinct giant jaguar (Panthera onca augusta), American lion (Panthera atrox) and the saber toothed cat (Smilodon fatalis), which is now the official fossil for the state of California! Several more recognizable and distinctly not-extinct felines like the cougar (Puma concolor) and the bobcat (Lynx rufus) also have been found in the tar pits.
Camels, horses & llamas
Two species of horses — the western horse (Equus cf. E. occidentalis) and the Mexican horse (Equus conversidens) — one species of camel — yesterday’s camel (Camelops hesternus) — and one species of llama — the large-headed llama (Hemiauchenia macrocephala) — have been found in the gooey depths of the tar pits.
Unfortunately, all the animals in this category are extinct today, so it’s hard to imagine what they looked like so many millennia ago. But even though it’s sad, it goes to show how important the research done here at the LaBrea Tar PIts is to understanding what the world looked like back then!
Canines
Most of the canines in this category you’ll recognize, as they’re still pretty commonly found in backyards and wildernesses all over Southern California. The gray wolf (Canis lupus) and gray fox (Urocyon cinereoargenteus) are two of them, so are the coyote (Canis latrans) and domestic dog (Canis familiaris).
The only extinct canine species that’s been found in the tar pits is the dire wolf (Canis dirus) — a Pleistocene-era wolf species that’s been found in North America, South America and eastern Asia. In fact, the La Brea Tar Pits are where the largest collection of this animal’s fossils have been found anywhere in the world!
Cattle
Among the remains found in the tar pits are a series of cattle species, though they weren’t necessarily used as domestic cattle back then.
There are over 300 individual remains of ancient bison (Bison antiquus) in the pits, which makes sense since they were one of the most prolific herbivores back in Late Pleistocene North America until around 10,000 years ago! The gentle giants traveled in herds of up to a thousand and grazed on small hedges, shrubs and grasses all over California.
Other extinct cattle species found in the pits include the long-horned bison (Bison latifrons), the shrub-ox (Euceratherium sp. cf. E. collinum) and the domestic sheep (Ovis aries) — the only species still present today.
Ground sloths
No one really thinks of sloths, much less giant sloths, when picturing the ancient animals of Southern California, but it’s true! Giant sloths once roamed the land here from about 4.9 million years ago to a mere 12,000 years ago — much longer than us measly humans have been around!
The three species of ground sloth found in the LaBrea Tar Pits include the Jefferson’s ground sloth (Megalonyx jeffersoniI), the Shasta ground sloth (Nothrotheriops shastensis) and the Harlan’s ground sloth (Paramylodon harlani). The Harlan’s ground sloth is the most predominant fossil of all the sloths found in the pits and has allowed scientists to recreate an extremely accurate image of the ancient creature — over 70 individuals have been found here with an astounding 30 skulls!
Humans
Out of all the animals and plants found in the La Brea Tar Pits, only one of the fossils has been of a human — a young woman between the ages of 17 and 25 years old who died around 10,000 years ago. We can only guess as to whether she was buried in the pit by her community or drowned in the tar on her own, but we do know that the La Brea Woman was around 4’ 10” and that she ate a diet of stone-ground meal. Other than that, the only other human evidence in the pit are some tool marks in some saber-toothed cat bones, though it’s hard to date them accurately.
Mammoths & mastodons
Mammoths didn’t have to worry about L.A. traffic, despite being the largest creatures on the proverbial roads back then.
Remains from both the American mastodon (Mammut americanum) and the Columbian mammoth (Mammuthus columbi) have been found in the tar pits and are the largest animal species excavated there as of yet. They both went extinct at the end of the Pleistocene era about 12,000 to 11,000 years ago as the last Ice Age came to an end and much of the megafauna on the continent slowly died out.
Rodents, shrews, rabbits & hares
There are too many of these little furry creatures to talk about each one in depth, other than to say that all of them aside from the deer mouse are still present in Southern California today!
- California ground squirrel (Otospermophilus beecheyi)
- Merriam's chipmunks (Tamias cf. T. merriami)
- Botta's pocket gopher (Thomomys bottae)
- Agile kangaroo rat (Dipodomys agilis)
- Pocket mouse (Perognathus californicus)
- Western harvest mouse (Reithrodontomys megalotis )
- Deer mouse (Peromyscus imperfectus)
- Southern grasshopper mouse (Onychomys torridus )
- Dusky-footed woodrat (Neotoma fuscipes )
- California vole (Microtus californicus)
- Desert cottontail (Sylvilagus audubonii )
- Brush rabbit (Sylvilagus bachmani )
- Black-tailed jackrabbit (Lepus californicus)
- Ornate shrew (Sorex ornatus)
- Crawford's gray shrew (Notiosorex crawfordi )
- Broad-footed mole (Scapanus latimanus)
Small carnivores
Of the many little critters that have gotten stuck in the sticky black goo, all of these smaller carnivorous mammals found in the La Brea Tar Pits are still alive and kicking today — at least, their descendants are.
They include:
- Long tailed weasels (Mustela frenata)
- American badgers (Taxidea taxus)
- Spotted skunks (Spilogale putorius )
- Striped skunks (Mephitis mephitis)
- Raccoons (Procyon lotor)
- Ringtails (Bassariscus astutus)
If you live in or near our luxury Southern California apartments, then be sure to take a trip to this one-of-a-kind museum and see the tar pits for yourself! You can even watch as scientists actively excavate the pits and discover new bones, fossils and artifacts from the murky, dark pools. It’s a must-see museum, for sure!
Enjoy!
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Featured photo courtesy Pixabay/mrganso
Colleen Ford is a South African who now lives on Oahu in Hawai'i. She loves to travel, camp, spearfish and hike. She's also part of a super cool canoe club and is pretty decent at it. Colleen enjoys Star Wars and also not being cold ever.
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