Sloth and ancient bison bones found deep below Los Angeles by tunnel diggers.

Giant sloths and ancient bison once ruled downtown Los Angeles.

So did ancient camels, mastodons and mammoths. But they were all wiped  away when the last ice age ended about 10,000 years ago.

But new traces of their dominion have just turned up by crews digging a tunnel for a new LA train line.

“We found bones!” the Los Angeles County Metropolitan Transportation Authority recently announced.

One bone belonged to a bison and the other, a giant sloth. The discoveries came on May 16 in a sandy clay layer some 16-feet under Crenshaw Boulevard.

Paleo Solutions laboratory handled the fossils and later, Gary Takeuchi of the La Brea Tar Pits and Museum helped identify the animals they once belonged to.

The first fossil fragment was pegged as the bison right proximal radius, or foreleg.

The bison bone found recently at left, a sample bison bone at right/Los Angeles County Metropolitan Transportation Authority

In ancient times, the animal would have looked like this.

Ancient bison/La Brea Tar Pits.

The second fossil was identified as a sloth’s proximal femur head fragment, or hip joint.

Sample sloth bone at left, sloth bone found at right/Los Angeles County Metropolitan Transportation Authority

“This is an amazing discovery,” the transit authority said.

The Harlan’s Ground Sloth, which weighed up to 1,500 pounds and stretched 10-feet in length, was the largest and most common of three species of ground sloth found at the Tar Pits.

It lived in the Los Angeles basin some 40,000 to 11,000 years ago.

And this is what it looked like.

Harlan’s ground sloth/La Brea Tar Pits.

The fossils will eventually be transferred to the Natural History Museum of Los Angeles County or other accredited facility.

This isn’t the first exciting find by work crews.

Earlier this year, bones belonging to an ancient camel and a mastodon or mammoth were found during work on a subway extension under Wilshire Boulevard.

“It is surprising to most people that camels were once native to Southern California,” Dr. Ashley Leger, Paleontological Field Director for Cogstone Resource Management said at the time. “Camel bones are quite rare in the fossil record of our area. We are very excited about what we might discover next in this fossil-rich area.”

And late last year, tooth, tusks and skull from ancient relatives of elephants were unearthed.

Unearthing the skull and tusks/Los Angeles County Metropolitan Transportation Authority

This is what the ancient mastodon probably looked like.


An illustration of an American Mastodon/La Brea Tar Pits & Museum.

Because fossils were expected to be unearthed during subway work, the transit authority has palaeontologists on site.

Photos Los Angeles County Metropolitan Transportation Authority La Brea Tar Pits and Museum

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Recovering newspaper reporter.

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