See the Ancient Creatures That Might Have Been Beneath Your Feet

“We found something.”

Jesse Shelmire, a paleontologist with the San Diego Natural History Museum, stood over the partial tooth of a Gomphothere, an elephantlike creature that roamed the area several million years ago. It presented itself amid 40 acres of dirt that the city is turning into a community park just north of Tijuana, Mexico. The tooth sat where a basketball court is planned and would have been lost to bulldozers had Shelmire not identified it.

Before the day was out, the tooth was on its way to the museum to join more than 1.5 million other fossils, a vast collection that shows how Southern California teemed with terrestrial and marine life millions of years before humans came along.

The collection includes evidence of all manner of species, from the bones of dinosaurs and huge marine mammals to bird eggs, tiny insects and barely visible shells. Each item is categorized and tagged for what it is, who found it, where it was found and when, making it a rich resource for scholars, other museums and the nonacademic curious.

The Nat, as locals know it, was founded in 1874 and grew into its current Balboa Park location in 1933. As part of its 150th anniversary celebration this year, the museum is bringing more of the paleontology collection into public view. A new, $5.1 million gallery below the main floor opened this month to display many items previously kept behind closed doors. A new research laboratory adjacent to the viewing area means that visitors can watch scientists investigate specimens and chat with them as they do their work. Two previous storage spaces, one of them miles away, were largely off-limits to the public.

“The anniversary gives us the opportunity to look ahead and set up the museum for the next 150 years,” said Judy Gradwohl, who became the museum’s first woman president and chief executive eight years ago after more than 30 years at the Smithsonian in Washington, D.C. “Our challenge is, ‘How do I pass along our collection to the next generation?’”

The museum has a biodiverse collection of 8.7 million specimens that reflect 1.9 billion years of regional history. While not nearly as large as the global collections in such elite institutions as the American Museum of Natural History in New York or the Smithsonian, San Diego’s holdings are unusual in that they were mostly found in one region: Southern California and the Baja California peninsula of Mexico. They range from fossils to flora, to recovered animal bodies stuffed and mounted through taxidermy, and to what may be the world’s largest collection of preserved rattlesnakes.

Many items were discovered at construction sites like the planned community park, where access is guaranteed through a California environmental law that requires developers to bring in paleontologists if evidence of life has emerged during land grading or construction.

As a new football stadium was being built on the campus of San Diego State University, parts of a giant bison emerged five feet below a parking lot where tailgaters once partied at the old stadium. A tusk of a mammoth skull was found during construction of a new building for the Thomas Jefferson School of Law. A whale skull emerged along Interstate 15. The skull of a 40-million-year-old Brontotheriidae, a rhinoceros ancestor, turned up in the nearby town of Oceanside, Calif., and half of an armored dinosaur was found three miles south in Carlsbad.

Other fossils were unearthed at apartment complex sites in the city, freeway embankments in the area and the nearby Camp Pendleton military base.

“Most states don’t protect these areas,” Shelmire said. “It’s kind of tragic when you think about it. There would be so much lost data, lost jobs.” And lost history.

The new viewing area and lab are named for Tom Deméré, the curator of the paleontology department who is now in his 46th year at the museum. On a tour of the permanent exhibit, he pointed out some of the largest animals in the museum’s collection — whales, bison, fish, walruses and dinosaurs — all discovered in the region and too big for shelves and storage drawers, where the majority of the paleontology collection is kept inside more than 400 metal lockers, now occupying an 8,000 square-foot warehouse adjacent to the new lab and gallery. The space resembles the final scene in “Raiders of the Lost Ark,” when the ark disappears into the recesses of a vast government storage facility.

“These are the traditional activities the museum does,” Deméré said, poking into random drawers. “We recognized the need to protect the fossils, to document and archive them to see what we could have lost forever.”

Some of the fossils have been out of sight since their discovery more than 100 years ago; many are millions of years old. Gallery windows at the lab now open to workers who peer into microscopes or chip away at extraneous rock before tagging each item. The windows open so they can explain to visitors what they are studying and how each specimen sheds another pinpoint of light on the region’s history.

The creation of the gallery and lab is one of several initiatives the museum is undertaking as part of the anniversary celebration. Another will surround the building with a garden composed of native and low-water vegetation to exemplify the area’s flora diversity. The museum has also joined with groups in San Francisco and Los Angeles to create the California Urban Nature Alliance, an organization to protect and improve green spaces.

“We like to think we punch above our weight,” Gradwohl said, mindful of leading a museum that has far fewer resources than other big city natural history museums. “It was a leap of faith to leave the Smithsonian for a midsize regional museum to see ways that bigger is not always better. Eight years later, I’m still thrilled to be here.”