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A forgotten fossil sitting in a museum drawer for nearly 100 years has turned out to be a game-changing Ice Age discovery.
Scientists have identified a previously unknown extinct spadefoot toad — Spea labreae — at the La Brea Tar Pits. It’s the first extinct amphibian ever found in Los Angeles and only the second Ice Age amphibian species discovered in North America, according to a study published Wednesday in the Journal of Vertebrate Paleontology.
The fossil was originally excavated from Rancho La Brea in 1929 but went largely unstudied until lead author Jose Alberto Cruz took a closer look.
He first assumed the bones belonged to a sick or injured member of a known spadefoot species. Instead, they belonged to one that no one had ever identified.
“Oh my god, this is a new species that is in a drawer,” Cruz told LAist. “And now it’s in the light to the world.”
The find marks Cruz’s first extinct species.
His research found the tiny amphibian was slightly larger than modern spadefoots.
Researchers named it Spea labreae after the iconic fossil site, though Cruz said the name also recognizes the museum staff who helped make the discovery possible.
The pint-sized amphibian could have a big story to tell.
Because frogs and toads are extremely sensitive to changes in climate and water, their fossils act as a snapshot of ancient environments.
Unlike birds, they can’t simply fly away when conditions change.
“ The birds, they can fly. If the conditions are very bad, they move,” Cruz said. “But in the case of toads, frogs … they can’t move a lot.”
That makes the discovery one of the strongest clues yet that Ice Age Los Angeles was much colder and wetter than it is today, said co-author Emily Lindsey, a vertebrate paleontologist at the La Brea Tar Pits.
“ If we’re trying to understand what Los Angeles looked like during the Ice Age, these are some of our best clues that can give us information about that,” she told LAist.
The team also found the first evidence that the Mexican burrowing toad once lived in Los Angeles, even though the species now survives only in southern Mexico.
Lindsey said climate shifts at the end of the Ice Age or the arrival of humans may explain its disappearance from California.
The newly discovered toad won’t get its own museum display when the La Brea Tar Pits reopens after renovations, but Lindsey said it will be featured alongside the insects, birds, plants and other animals that helped shape the Ice Age ecosystem.
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