Researchers have identified Spea labreae, a previously unknown extinct spadefoot toad from the Pleistocene of Los Angeles, showing how small amphibian fossils can provide valuable evidence about ancient climate and environmental change.
Publication date: 17 August 2026
New species hidden in a historic fossil collection
Scientists have identified a new extinct amphibian species from fossil material preserved at the famous La Brea Tar Pits in Los Angeles, California. The species, named Spea labreae, is a Pleistocene spadefoot toad that had remained unrecognised in museum collections for decades. The discovery was highlighted by ScienceDaily on 16 August 2026 and is based on research published in the Journal of Vertebrate Paleontology. (ScienceDaily)
The discovery is particularly notable because Pleistocene amphibian fossils are uncommon. According to the research announcement from the Natural History Museum of Los Angeles County, S. labreae represents only the second extinct Pleistocene amphibian identified from North America. (Mirage News)
The species was recognised when researchers re-examined previously understudied amphibian and reptile material from the La Brea collections. Detailed comparisons of fossil bones with modern spadefoot toads and specimens held in major herpetological collections revealed anatomical features sufficiently distinct to identify the fossils as a separate species. The investigation included comparisons with 80 specimens from the Natural History Museum of Los Angeles County and the University of California, Berkeley's Museum of Vertebrate Zoology. (Mirage News)
Why an extinct toad matters
At first glance, the discovery of a relatively small amphibian may appear less spectacular than the mammoths, dire wolves and sabre-toothed cats associated with the La Brea Tar Pits. Scientifically, however, amphibians can provide a different type of information about ancient ecosystems.
Frogs and toads are generally sensitive to environmental conditions and tend to have relatively limited movements compared with many large mammals. Their fossil presence can therefore provide clues about local environmental conditions, including the availability of suitable habitats and changes in climate. (Mirage News)
The researchers also identified the first fossil record from the southwestern United States of the Mexican burrowing toad, Rhinophrynus. This genus is no longer found around modern Los Angeles; its nearest present-day populations are in southern Mexico, roughly 2,500 kilometres away. The combination of the extinct S. labreae and the former presence of Rhinophrynus provides additional evidence of substantial environmental and geographical changes since the end of the last Ice Age. (Mirage News)
Significance for zoology and palaeontology
The finding demonstrates the continuing scientific value of natural-history collections. Fossils collected many decades ago can yield new information when examined using modern taxonomic knowledge and comparative methods.
For zoology students, the discovery is an excellent example of how taxonomy, comparative anatomy, palaeontology, biogeography, ecology and climate science can be integrated to reconstruct the history of life.
It also highlights an important principle in biodiversity research: species that appear insignificant because of their small size may provide exceptionally useful evidence about ecosystem change. Amphibians are particularly valuable in this context because of their close association with environmental conditions.
The discovery of Spea labreae also suggests that fossil collections may contain other previously overlooked amphibian and reptile material. Researchers noted that the delicate skeletons of these animals are less likely to survive fossilisation than the robust bones of large mammals, meaning the known fossil record may represent only a fraction of past amphibian diversity. (Mirage News)
A lesson for modern biodiversity research
The Ice Age history revealed by the La Brea fossils has relevance beyond palaeontology. Understanding how species responded to past environmental changes can help scientists investigate how modern animals may respond to rapidly changing climates.
The disappearance of S. labreae and the former wider distribution of Rhinophrynus illustrate that species ranges are not fixed. Climate, vegetation, water availability and other ecological factors can reshape the distribution of organisms over geological time.
The discovery therefore adds another piece to the complex ecological history of Ice Age Los Angeles and demonstrates why preserving natural-history collections remains important for modern biological research.
Sources
ScienceDaily, A New Ice Age Species Was Hiding in La Brea Tar Pits Fossils for Decades, 16 August 2026. (ScienceDaily)
ScienceDaily – Top NewsNatural History Museum of Los Angeles County, research announcement on Spea labreae, 5 August 2026. (Mirage News)
Research announcement reproduced from the originating institutionJournal of Vertebrate Paleontology, publication reporting the description of Spea labreae. (Mirage News)
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