Scientists excavate bison fossils with dental picks at the La Brea Tar Pits in Los Angeles, Calif. on Oct. 23, 2013. Jae C. Hong/AP

An exploratory subway shaft dug just down the street from the Los Angeles County Museum of Art has uncovered a treasure trove of prehistoric artifacts, the Los Angeles Times reported Saturday.

They include mollusks, asphalt-saturated sand dollars and possibly the mouth of a sea lion dating to 2 million years ago, a time when the Pacific Ocean extended several miles farther inland than it does today.

"Here on the Miracle Mile is where the best record of life from the last great ice age in the world is found," paleontologist Kim Scott told the Associated Press.

The area, dotted today with museums, restaurants, boutiques and apartment buildings, also includes the world-famous La Brea Tar Pits. It was there that animals of another age got stuck in the pits' oozing muck, which preserved their skeletons for millennia.

The shaft, dug ahead of work scheduled next year to extend a subway line across LA's west side, is now revealing far more material, including geoducks, clams, snails, mussels and even a 10-foot limb from a pine tree of the type normally now found in central California's woodlands.

The Los Angeles County Metropolitan Transportation Authority is working with Cogstone Resource Management and the nearby George C. Page Museum to identify and preserve the artifacts.

More such discoveries are expected when excavation work begins on a nearby subway station.

"LA's prehistoric past is meeting its subway future," noted transit authority spokesman Dave Sotero.

The subway dig isn’t the first time ice age fossils have been discovered in the area. In 2009, the George C. Page museum announced it had found the largest known collection of fossils from the period, unearthed during the construction of an underground parking garage, the LA Times reported. A worker’s bulldozer hit the skeleton of a Columbian mammoth, a beast with 10-foot-long tusks, the bones all nearly intact, the newspaper said.

Al Jazeera and the Associated Press