The Los Angeles County Metropolitan Transportation Authority (Metro) announced that two more fossils of ancient animals were discovered as its crew worked on the Crenshaw/LAX Transit Project 16 feet under Crenshaw Boulevard on May 16.

The Metro, with the help of an expert, identified the fossils as bone fragments coming from two different giant animals that used to roam the Los Angeles basin at least 10,000 years ago.

Identifying The Fossils

The Metro enlisted the help of paleontology experts from Paleo Solutions laboratory to prepare and stabilize the discovered bone fragments and, on May 24, Gary Takeuchi from the La Brea Tar Pits and Museum confirmed that the fossils match the bones of an ancient bison and a giant sloth.

Officials say that if the unknown bone fragment belongs to the Harlan's Ground Sloth, the animal could have easily grown up to 10 feet in length and weighed in at 1,500 pounds. However, the sole bone fragment that the Metro workers found is not enough to actually determine its species, even if the Harlan's Ground Sloth is the most common of the three species that frequented the area during the late Pleistocene period.

The Metro says that both fossils will eventually be transferred to the Natural History Museum of Los Angeles County for permanent curation. If not, another accredited repository will take them.

More Fossils As The Subway Extends

This is not the first time The Metro crew unearthed fossils from ancient animals during an expansion project.

On April 12 and 13, workers excavating for the Metro Purple Line Extension also unearthed two fossilized bones beneath Wilshire and La Brea Avenue. The first fossil was the radioulna — a combination of forearm bones between the elbow and wrists — of an ancient camel, while the other bone is the thigh bone of an ancient elephant — a mastodon or mammoth, though not a woolly one. The femur is about 36 inches in length and is supposedly very robust to support the mammoth's weight.

"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," Cogstone Paleontological Field Director Dr. Ashley Leger said at the time of discovery.

In November 2016, workers dug up a nearly complete mastodon skull, teeth fragments, and tusk on the same site.