An exploratory dig for an expansion of the Los Angeles subway system has unearthed a variety of prehistoric fossils, including ancient mollusks, sand dollars, and a possible portion of a sea lion's jaw dated two million years old.
L.A. officials expected they'd happen upon some unique objects, as the planned Westside subway extension ventures into the vicinity of the La Brea Tar Pits, a stratum of sediment featuring sand and naturally occurring asphalt -- a perfect mixture for fossil preservation.
"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 Los Angeles Times, "you're walking along an ice age shoreline."
The "Miracle Miles" is the name given to a stretch of L.A.'s Wilshire Boulevard between Fairfax and Highland Avenues.
The Los Angeles County Metropolitan Transportation Authority is coordinating with researchers from nearby Cogstone and Page Museum in order to properly collect, identify, and preserve important findings.
Previous construction efforts near the La Brea Tar Pits have turned up bits of prehistoric mammals. And in 2009, a bulldozer came across the perfectly intact skeleton of a Columbian mammoth with 10-foot-long tusks.
Depending on how deep the digging goes, the tar pits mostly turn up materials dating between 100,000 to 330,000 years old. But much older fossils have been found, pieces of older rocks having long ago washed into the tar fields and been preserved. Such is the case with the suspected sea lion jaw, which was found last week trapped inside a rock estimated to be two million years old.
The tar pits were formed as petroleum from now-dry oil fields slowly oozed the the surface, creating massive bogs that trapped and preserved animal remains.
The current dig is meant to test the soil composition in the area as engineers prepare to extend the subway line. But actual construction of the subway won't begin until next year. Officials expect more findings as the digging continues.
"Here in Mid-Wilshire," said Dave Sotero, a Metro spokesman, "L.A.'s prehistoric past is meeting its subway future."
[Los Angeles Times]