A new species of rocket frog, known as Dryadobates erythropus, has been identified from a single specimen collected in 1963. This finding, published in the journal Zootaxa, highlights the species’ likely extinction in the wild due to habitat destruction. Researchers from the University of São Paulo (USP) and the Smithsonian Institution collaborated on the study, shedding light on the biodiversity that once thrived in the Tarumã neighborhood of Curitiba, Brazil.
The sole known specimen of this frog was collected by American herpetologist Doris M. Cochran during a field study in Brazil. The specimen, which measures approximately 14 millimeters, is now housed at the Smithsonian’s National Museum of Natural History. Despite extensive surveys conducted over the past six decades, no additional specimens of this frog have been found, leading researchers to conclude that it is “probably extinct.”
Loss of Biodiversity in Curitiba
The area where D. erythropus was discovered has undergone significant transformation since the 1960s. Once characterized by streams, open fields, and wetlands, the landscape has been overtaken by urban development, including a racetrack and a large shopping mall. Taran Grant, a professor at USP and the lead author of the study, noted the drastic changes to the habitat, stating, “Given that the habitat of D. erythropus has been destroyed and that no other specimens have been collected in extensive surveys in various locations in São Paulo and Paraná over the last 60 years, it’s most likely extinct.”
This newly identified species belongs to the genus Dryadobates, which contains at least 13 species. Of these, four species were declared extinct between the 1960s and 1980s. The name Dryadobates is derived from Greek mythology, referring to the nymphs of the trees, while erythropus translates to “red foot,” a nickname for rural workers in northern Paraná.
In the study, researchers traced the frog’s original habitat through meticulous investigation of Cochran’s travel diary. This document was crucial in confirming the location of the specimen’s collection. Although there was initial confusion regarding the collection site, the diary indicated that the frog was captured in a large field filled with anthills and cow-chewed bushes in Tarumã.
Challenges in Genetic Analysis
Despite attempts to analyze historical DNA (hDNA) from the specimen, researchers faced challenges due to its state of preservation. Grant’s team sought to extract DNA but found only human contamination and bacteria, indicating that the frog may have died before it was preserved properly in alcohol. “The DNA probably began to degrade much earlier than it would have if the frog had been preserved in alcohol,” Grant explained.
The team’s efforts to identify genetic material were hampered by the specimen’s condition, which did not yield fragments suitable for molecular identification. As a result, the classification of D. erythropus relied on distinct morphological characteristics rather than genetic data.
Grant emphasized the importance of this research, not only as a reminder of the urgent need to protect natural habitats but also as a tribute to the contributions of women scientists like Cochran and entomologist Doris H. Blake. Their efforts in the field have provided valuable insights into species that may otherwise have been forgotten. “If it weren’t for them, we wouldn’t know that we once had this species,” Grant concluded.
As conservation efforts continue, researchers hope that advancements in technology may one day allow for genetic identification of species from historical specimens, contributing to the understanding of biodiversity loss and the importance of habitat preservation.
