Just before Thanksgiving, Metro workers found themselves swept back in time. While tunneling the route of the Purple Line, they dug up a tusk, teeth and part of a skull belonging to an ancient mastodon or mammoth.
It's not the first — or the last — time this has happened. Fossil finds are a periodic occurrence in the area in the Miracle Mile area, which is rich with such deposits.
So what did Metro do next? Here's how it works whenever this happens.
1. Work Stops
During digs, Metro has someone on-site, 24/7 for just such an occurrence. When any fossils are found, work in the immediate area stops until the fossil(s) can be safely removed.
2. They Call An Expert
In this case, it's paleontologist Kim Scott, who works for Cogstone Resource Management. Metro has a contract with the company, which specializes in evaluating paleontological, geological and archaeological finds.
Take Two's A Martinez spoke with Scott, who tells him him finds like the recent pre-Thanksgiving one are common.
"I've been doing paleontology in California for about 20 years now," she says. "And typically once you get about ten feet deep you start finding ice age animal bones. That's in our valleys. Now if you go to hill and you have older sediments, well that's different. But in our valleys: Go ten feet down and you'll start hitting elephants. The good news is it takes a lot of dirt to end up with something. So we do find them on construction sites."
3. The Fossils Get Cleaned Up
Fossil finds are removed from the area, cleaned up and prepared for study. The process can take anywhere from a few hours to a few days, depending on the condition of the bones. In the meantime, the area where the bones are found is monitored because where there's one ancient mastodon tooth there might be another.
"The tusk and the skull have both been removed already, so they've been taken from the area," Scott tells Take Two. "We will monitor that area very carefully for more bone. Because once you get a couple bones, you might have a bone bed. We now have two known individuals so there's a good chance we'll se more fossils. But right now the skull is waiting to get transported to our laboratory where it's going to be prepped out and made very pretty and then we can figure out if it's a mastodon like we think or a mammoth."
4. They're Sent Out For Study
If the fossils are found in asphalt, they're sent to the Natural History Museum. If they're found in tar, they're sent to the La Brea Tar Pits. Either Way, researchers finally get a chance to look at the fossils and see what they can learn.
"We find things all the time," Scott tells Take Two. "It's just that frequently, it doesn't get to the point where the media gets called out. If it's a really pretty fossil then we start saying, 'Hey. you guys can move on and get some great press for this!'"
When LACMA was building its parking lot about a decade ago, workers hit 23 separate fossil deposits. Experts at La Brea Tar Pits have been studying them ever since.
What's so special about this find?
"The fact there's been some mastodon material from this most recent find is somewhat significant because they tend to be more of a rare species," Dr. Emily Lindsey with the, assistant curator and excavation site director at the La Brea Tar Pits, tells KPCC. "We find a lot of mammoth remains but not as many mastodon remains."
Both animals are classified as Proboscideans, a group of that spans ancient elephants as well as modern day ones.
If a specimen looks promising, researchers may conduct radio-carbon dating to determine its age. We know these most recent finds come from the last Ice Age during the Pleistocene Era, but they could be as recent as 12,000 years old or they could date back 100,000 years.
To hear the full segment click the blue player above