The La Brea Tar Pits know no mercy. The world’s most productive urban paleontological dig, they’ve yielded a stockpile of fossils that spill over from the main galleries of the La Brea Tar Pits Museum and into the lab and the cabinets and lockers that line the hidden hallways. “They essentially go around the entire building,” says Emily Lindsey, assistant curator and excavation site director at the museum, nodding to the floor-to-ceiling specimen trays that telescope down a long corridor. Then she slides out a tray to reveal a deformed jawbone from the Pleistocene epoch, when Mid Wilshire was still a savanna woodland and its traffic amounted to mammoths and camels and dire wolves.
If Lindsey were to guess how long it might take the staff to clean and identify its current cache, she figures 15 years wouldn’t be unreasonable. The sheer plenitude of research material is what makes the place so special to someone like her , but also overwhelming. That’s why Lindsey and Co. are “a little nervous” about what construction crews working on the Purple Line’s Fairfax station will turn up when they reach the tar—or, rather, “naturally occurring asphalt”—lurking beneath Wilshire this summer.
“Once they start getting below that, I think we’re going to have a very exciting time recovering fossils,” says Ashley Leger. She’s a paleontologist with Cogstone Resource Management, the company Metro hired to ensure that fossils make it out of the Purple Line construction sites intact. Her first big find along the subway extension came last November, when workers at the site of the future La Brea station unearthed a small mammoth or mastodon skull, its tusks still attached. Leger hopped to it, hoping to excavate the bone and safeguarding it with a covering of burlap and plaster. “We actually use damp toilet paper to coat the fossil first,” Leger says, “to provide a barrier between the bone and the sticky plaster so that the plaster won’t damage the bone.” Fifteen hours later, the bundle just needed to dry before being trucked to Cogstone’s lab in Riverside, where it will be studied and made museumworthy.
Because there’s no naturally occurring asphalt at the La Brea station site, ancient mementos pulled from its sedimentary layers will eventually wind up at the Natural History Museum. Since the Fairfax site does have the petroleum byproduct, fossils found there will land at the Tar Pits Museum, but only after the laborious process of extracting and ridding them of the primordial black goo.
Like a bad boyfriend, asphalt is clingy and smelly and disorganized. Churning ever so slowly, it jumbles together the vestiges of plants and animals that existed thousands of years apart from one another.
Leger and her team will remove entire hunks of fossil-laden material, packing them into giant wood boxes. Twenty-three such boxes were filled when LACMA, the tar pits’ neighbor, built a subterranean parking lot in the aughts. It’s taken staff this long to get through just seven of them. So Cogstone will be responsible for prepping the Fairfax station finds , making them shelf ready for Emily Lindsey and her colleagues to choose from. It’ll be years before you get to see them, which works thematically: Fossils are all about long time lines.