Metro crews working on excavations for the Wilshire-La Brea Purple Line subway station have unearthed what appear to be bones of two “ancient elephant relatives” at the site in the past week. Metro announced yesterday that these are the first mammal fossils found during the project. They include “a three-foot section of tusk and mastodon tooth fragments” from an adult animal and “a partial skull with tusks of a possibly much younger mammoth or mastodon,” at the southwest corner of Wilshire Boulevard and La Brea Avenue, about 15 feet below street level.
According to a Metro press release:
“Mammoths and mastodons are both distantly related to elephants. Columbian mammoths found in California were slightly larger than the American mastodon. Mammoths were more of a plains animal with tall “washboard-like” flat teeth that could stand up to chewing tough grasses with silica, while mastodons tended to roam brush and forests while eating mostly leaves, fruit, and flowers — so their teeth had low crowns. Both species went extinct in North America at least 10,000 years ago during a wave of large animal extinctions following the last Ice Age.”
Similar large animal fossils have been found at the La Brea Tar Pits, just a bit further west along Wilshire, so it’s no surprise that new fossils have been found during the subway project. In fact, anticipating such finds, Metro hired paleontologists to consult on the excavations and any discoveries.
If and when fossils are found, Metro’s policy is to stop all work in the area, until the items can be preserved and removed. And the new finds are already being processed.
“Both the tusk section and skull have been encased in plaster — similar to that used in making casts for humans — in order to be removed from the site intact and taken to a lab for further analysis. An analysis of the teeth and other features of the skull will tell whether the animal was a mammoth or mastodon. The skull will ultimately be handed over to the Natural History Museum of Los Angeles County.”
According to Emily Lindsey, Assistant Curator at the La Brea Tar Pits and Museum, that institution has a memorandum of understanding with the Purple Line project, under which fossils found in tar-like sediments will go to the Tar Pits Museum, while those found in other sedimentary materials – like the new Wilshire-La Brea discovery – will go to the NHM (though there could be some slight variations in that plan, depending on other details of specific finds). Lindsay said that because the area has such rich fossil deposits, she expects there will be more finds as the excavations continue…and that there will probably be a number of tar-based fossils discovered when the excavations proceed toward the Wilshire-Fairfax station, where that kind of material becomes more plentiful.
Lindsey noted that the Tar Pits Museum’s major project for the last 10 years has been excavating and analyzing 23 big fossil deposits unearthed when the new LACMA parking garage was built…and she expects the subway project to yield similar treasures.
According to Lindsay, mammoth fossils are fairly common in the area, but “mastodons are pretty rare, so that would be a little more interesting, scientifically,” if that’s what this most recent find turns out to be. However, “It’s pretty cool either way.” In general, she said, the city’s rich deposits of fossils are a “great reminder of what a wonderful place L.A. is. They have a remarkable ability to tell us about the past.”
For more photos of Metro’s recent Wilshire-La Brea finds, see http://thesource.metro.net/2016/11/30/tooth-tusks-and-skull-from-mastodon-andor-mammoth-unearthed-during-purple-line-construction/