New Ice Age Amphibian Species Discovered at La Brea Tar Pits

Researchers at La Brea Tar Pits have identified a new extinct amphibian species, Spea labreae, from fossils that have been in the collection for decades. This spadefoot toad lived during the Ice Age in what is now Los Angeles. The discovery is notable as it is only the second extinct Pleistocene amphibian found in North America, with the first being a tree frog from Florida.

The study, published in the Journal of Vertebrate Paleontology, was led by Dr. Alberto Cruz, who initially set out to study the Tar Pits' reptile and amphibian collections. Cruz, a Research Associate at La Brea Tar Pits and a researcher at Mexico's SECIHTI Centro de Investigación Paleontológica Quinametzin, noticed unusual features in the specimens that distinguished them from known spadefoot toads. After extensive comparisons with modern specimens, Cruz confirmed the fossils represented a new species.

This discovery highlights the potential for museum collections to yield new scientific insights, even from specimens collected many years ago. Dr. Emily Lindsey, Curator at the Samuel Oschin Global Center for Ice Age Research, emphasized the ongoing potential for new findings at La Brea Tar Pits.

Amphibians like S. labreae are valuable for reconstructing past climates due to their sensitivity to environmental changes. They serve as climate proxies, helping scientists understand local environmental shifts during the Ice Age. However, their delicate skeletons make them rare in the fossil record, making this find particularly significant.

The research also uncovered the first record of the Mexican burrowing toad, Rhinophrynus, in the southwestern United States, suggesting a much broader historical range for the species. This finding, along with the extinction of S. labreae, adds to the understanding of environmental changes at the end of the last Ice Age.