Subway dig in L.A. yields fossil trove

Not all of the fossils in North Hollywood have facelifts and tummy tucks. Just ask the Los Angeles County Metropolitan Transportation Authority (MTA), which earlier this month announced paleontological finds that it made while extending a subway line through Hollywood and into the San Fernando Valley.

During the digging, which began in 1987 and ended last June, researchers recovered more than 2,000 fossil specimens. Their origins span 16.5 million years. The fossils, many representing new species, provide sharp insight into the area’s ancient climate and environment, says the MTA report’s author Bruce Lander of Paleo Environmental Associates of Altadena, Calif.

Many of the finds recovered from excavations beneath Hollywood Boulevard—such as isolated bones and teeth of mastodons, giant ground sloths, bison, and camels—mirror evidence of species found in the nearby La Brea tar pits, notes Lander.

These fossils indicate that about 8,000 to 9,000 years ago the area was what Lander calls a savanna woodland. Pollen from plants such as Mormon tea, a woody shrub native to deserts, suggest that conditions then were much hotter and drier than today. But it wasn’t always dry: A large jam of fossil poplar logs testify to a flash flood along an ancient river.

Other spots along the new subway yielded redwood pollen and logs of incense cedar that date to 46,000 years ago. They indicate the climate then was much cooler and wetter than now.

People joke that an earthquake may someday dump Los Angeles into the ocean, but the area was underwater in the geologically recent past. Marine fossils are the real treasures among the subway finds, says David P. Whistler, curator of vertebrate paleontology at the Natural History Museum of Los Angeles County in Los Angeles, which received all the MTA fossils.

Of the 64 extinct species of fish unearthed, 39 were new to science. Many were varieties related to species, such as lanternfish and deep-sea smelt, that today live 0.5 to 1 mile below the surface. Other specimens represent the only fossil finds of some modern fish, including fangtooths and spookfishes.

Most of the deep-sea fossils were recovered from sediments 8.5 million to 7.2 million years old, says Whistler. Rocks of the same age a few miles away contain only shallow-water fish species. This suggests that the Los Angeles area at that time was at the steep edge of the continental shelf.

Fossils of sea stars and some other soft-bodied invertebrates were remarkably well-preserved because the remains had been quickly covered with fine sediments, says Lindsey T. Groves, an invertebrate paleontologist at the museum. He notes, “These [marine fossils] aren’t as visually interesting as the tar-pit fossils, but to some of us, they’re much more exciting.”