A rich fossil deposit in northeastern Brazil has provided paleontologists with a new look at a time when many strange amphibians—including a "fire frog"—thrived in ancient swamps.
The unusual fossil amphibians, described by Field Museum paleontologist Kenneth Angielczyk and colleagues in Nature Communications on November 5, were found in Brazil’s Paranaíba Basin and date back to the early part of the Permian period, about 278 million years ago.
Fossils have been known from this area for decades, but, Angielczyk says, it was the search for a particular kind of animal that drew him and his co-authors to take another look.
“We actually got started there with the hope of finding early therapsids"—protomammal human cousins that thrived during the Permian. (Related: "Our Prehistoric Cousins Had Demonic Skulls.")
Up until now, most of what was known about this time in Earth's history came from North America. These rocks, now in Texas and Oklahoma, were close to the Equator during the early Permian and provided only a narrow view of what life was like then.
“We are especially in the dark about what was going on in Gondwana,” or the large southern supercontinent that existed at the time, says Angielczyk, whose work was supported by the National Geographic Society's Committee for Research and Exploration.
The Paranaíba Basin seemed like a good place to look to start filling in some of the global gaps: For one, it was located in the subtropics, south of well-known territory, Angielczyk says.
And while the team has yet to uncover any therapsids, Angielczyk says, the explorations have turned up a variety of other odd fossils. (Learn more about prehistoric animals.)
“The Paranaíba Basin happens to have had a number lake and wetland environments at the time, and the fossils we’re finding show that there was a diverse community of plants, fish, sharks, and amphibians there, with reptiles present on land," Angielczyk says.
In addition to some previously known animals—such as a giant, crocodile-like amphibian named Prionosuchus plummeri—the researchers have discovered some new animals, including the salamander-like Timonya anneae and Procuhy nazariensis, whose name translates to “the fire frog from Nazaria" (a combination of the Timbira language and the name of a local town).
More Discoveries Await
“It is very exciting,” says Museum of Western Colorado paleontologist Julia McHugh.
In addition to filling a fossil gap in a previously little-known part of the world, the Paranaíba Basin has the potential to explain how some of these weird amphibians evolved and moved around the planet, says McHugh, who wasn't involved in the new study.
For example, the discovery of a type of amphibian called a dvinosaur in the Paranaíba Basin adds a new point on the map along with finds from North America and Russia, she says. “This locality bridges the biogeographical gap between disparate species of the group,” McHugh says. (Also see "Pictures: New Dinosaur, Crocodile Cousin Found in Brazil.")
And the work in Brazil isn’t yet done. Angielczyk says that efforts are continuing to dig into what might be hidden at this particular spot.
"It’s taken us a while to figure out the best places to look for fossils, and we only found our first reptiles this year,” he says.
The “fire frog," he hopes, is the just the spark for many discoveries to come.