New frog families are discovered in Pico da Neblina – 12/15/2023 – Science

A scientific expedition in 2017 to the country’s highest point, Pico da Neblina, in the state of Amazonas, revealed a still unknown diversity of species, including two new families of amphibians from the group known as brachycephaloids (small frogs with the fourth finger). elongated and who do not usually jump long distances).

The first species, named Caligophryne doylei (the genus name comes from the Latin “caligo”, which means mist, and “phryno”, which is Greek for frog, while the specific epithet “doylei” is in honor of Arthur Conan Doyle, author of Sherlock Holmes), is a representative of the brachiocephaloid group of medium size, approximately 3 cm in size, head with a thin snout and the body covered in wrinkles. He is the only representative of the new family Caligophrynidae.

The second species, Neblinaphryne mayeri (the genus means “Neblina frog”, and the species honors General Sinclair James Mayer, from the Defense System, Industry and Academy division of the Brazilian Armed Forces), is also endemic to Pico da Neblina and was included in the Neblinaphrynidae family. Its lineage is older than Caligophrynidae, and the group presents characteristics considered more primitive in relation to other frogs in the Brachycephaloidea.

The expedition was coordinated by herpetologist (student of reptiles and amphibians) and professor at the USP Biosciences Institute Miguel Trefaut Rodrigues and included members of his laboratory, including biologists Renato Recoder and Sérgio Marques-Souza. The article describing the two new species, genera and families of frogs was published in the specialized journal Molecular Phylogenetics and Evolution and also included the participation of researchers from France and the United States.

Pico da Neblina is 2,995 m high and is located in Serra da Neblina, on the border of Brazil and Venezuela, in the Pico da Neblina National Park region, whose territory is between the municipalities of Santa Isabel do Rio Negro (AM) and São Gabriel da Cachoeira (AM).

Part of the base of the park is within the Yanomami Indigenous Territory (TI Yanomami). To reach the peak, you need a Brazilian Army helicopter. The team had help from the Armed Forces.

The scientists carried out field work for eight days, where they collected several specimens of frogs, lizards and snakes. After the expedition, the material was taken to the laboratory and placed in the Herpetology Collection of the USP Zoology Museum, in Ipiranga, south of São Paulo.

The detailed work of separating (sorting) the collected material, as well as analyzing the individuals to find out whether they were different species or not, took five years. In the meantime, another article, describing two new species of lizards of the genus Riolanahas already been published.

In the study, scientists carried out comparative work on the molecular (genetic material), morphology (such as external characteristics and internal anatomy) and calibrated the phylogenetic tree for the common ancestors of each lineage (calibrating the tree means, roughly speaking, placing a date — in millions of years—from when that branch split, based on existing knowledge from other studies with DNA and fossils).

The new finding is surprising because it is rare to describe a new family for vertebrates. “The first group to separate was the family Neblinaphrynidae [do sapinho-da-Neblina]about 55 million years ago [coincide com a origem do grande grupo Brachycephaloidea]. And the other, Caligophrynidae, was more recent, around 45 million years ago”, explains Rodrigues.

As the two species are totally different from the other families already known for the group, the most plausible hypothesis is that the separation with the other brachycephaloid lineages occurred shortly after the event of uplift of the massif where Pico da Neblina is located, and from then on the group was “stuck in time”. “They could really be relics of the past, but they could also be representatives of a much greater diversification that only they are left with. We have no way of knowing that,” he said.

The idea that this diversification occurred on all peaks of the mountain range is not unlikely. Already well-established studies in biology describe how tepuis (types of high-altitude fields in mountains in the middle of the Amazon) are environments with a high incidence of endemic species, those that are exclusive to a place.

“The expeditions to the tepuis in the Brazilian Amazon were carried out in the last century, and we had almost no information. There were some more recent studies from Venezuela and the Guianas, but nothing from Brazil. Now we hope to be able to sample diversity in other points that we collected samples, like the Imeri mountain range”, he explains.

Rodrigues also led an expedition to this peak, which is on the north side of the Serra da Neblina. According to him, many new species were also discovered there, but he cannot yet talk about them before official publication in a scientific study. “What I can say is that these places are cradles for the formation of species, and at the same time they are museums of biodiversity, because they preserve very old things, which diversified a long time ago”, he concludes.