New Ice Age spadefoot toad species unearthed from Los Angeles tar pits

While cataloguing amphibian specimens from the La Brea Tar Pits, paleoecologist J. Alberto Cruz noticed a hip bone that did not match any existing spadefoot toad. By comparing it with global spadefoot samples, he concluded it represents a new species that lived during the last Ice Age, about 45,000 years ago, marking only the second such amphibian fossil found in North America. The bones are larger than those of modern spadefoots and feature a fused sacrum-urostyle, distinguishing the species.

The discovery, detailed in the Journal of Vertebrate Paleontology, provides rare insight into ancient climate, as amphibians are highly sensitive to environmental conditions. The team also identified a fossilized Mexican burrowing toad far north of its present range, indicating historic habitat shifts. Experts emphasize that such delicate fossils, though scarce, can reveal temperature and humidity patterns of the period.