L.A. Underwater: The Prehistoric Sea Beneath Us is now open at the Natural History Museum of Los Angeles County (NHM).

The exhibit, which opened May 2, chronicles the prehistoric time when the land that is now Los Angeles was underwater and features rare fossils found across the L.A. region — from metro digging discoveries to a fossil found in a Lincoln Heights backyard and ranging from a few million to more than 70 million years old. 

Visitors will view rare fossils from across the L.A. region and encounter huge cinematic elements showcasing sharks the size of school buses, glowing deep sea fish, giant tuskless walruses, a 10-million-year-old whale skull discovered in Lincoln Heights, and other awe-inspiring species that roamed ancient L.A. 

The exhibition features nearly 40 fossils and specimens showcasing the region’s vast prehistory, including an ammonoid fossil that dates from nearly 75 million years ago; the 13- to 15-million-year-old Coursen’s Strange Seal; a 10,000- to 50,000-year-old saber-toothed cat skull and a shell discovered in modern L.A. soil.

Many of these fossils were found by everyday Angelenos — from construction workers building the Metro line to discoveries in local neighborhoods by museum visitors. The exhibition is organized into sections to help tell the story of our underwater past, beginning with explaining what fossils are and what they can tell us about the past. Another section of the exhibition highlights the many habitats that comprised L.A.’s prehistoric ocean, from sunlit coastal waters to the darkest depths.

A notable specimen is a 10-million-year-old whale skull that was discovered in 1931 by plumber F.W. Maley while digging an irrigation ditch in the Lincoln Heights neighborhood, which is located east of Downtown Los Angeles inone of the city’s oldest neighborhoods. This whale, Mixocetus elysius, was one of the largest baleen whales inthe world at the time of its life, with today’s whales being much bigger. The discovery of the skull and new prehistoric species helped scientists understand the evolution of the modern-day whale. Visitors will see it brought to life through a huge immersive wall projection. This section of the exhibition will focus on giant sea life, with some animals like the leatherback sea turtle still swimming near L.A. today.

L.A. Underwater will also address how ancient plankton transformed into the oil beneath L.A., creating a legacy of fossil fuels that has contributed to the city’s overall growth and wealth. Just as scientists use fossils to better understand the landscape of L.A. during different stages of its history, visitors will learn how to analyze specimens and identify clues that tell us stories about L.A.’s past. Using an interactive giant map of L.A., visitors can find fossils near them — and potentially the next great discovery!

Visitors will also be able to review a linear geological timescale demonstrating when L.A. began to emerge from the ocean as it made its way towards its current form, as well as the potential effects of climate change that threaten the city’s future.

L.A. Underwater is free with museum admission. Learn more at NHM.ORG/underwater.