It was already, in its own time, a living fossil, and it was an evolutionary oddity, paleontologists say: the Tanyka amnicolarecently discovered in Brazil, had a jaw that is a real puzzle.

There are many animals that today are considered “living fossils”. This is the case, for example, that long considered extinct, it has continued to swim in the Earth’s oceans since the time of the dinosaurs.

Also the horseshoe crabs which were from Covid-19, appear in the fossil record hundreds of millions of years ago. And many sharks seem practically unchanged in relation to their ancestors from the Cretaceous period.

But, although the Tanyka amnicola was last seen around 275 million years ago, was already, in his own time, a living fossil.

It was also a creature extremely strange. So strange, in fact, that paleontologists came to think they had in front of them a anomaly ancient when they discovered the first jaw of this animalwhich has an appearance similar to a salamanderin a dry riverbed near the Amazon rainforest in Brazil.

“The jaw has a strange twist that drove us crazy trying to understand what it was. We thought about it for years, wondering if it was some kind of deformation”, he recalled. Jason Pardopaleontologist at the Field Museum in Chicago, in a statement published on .

But as Pardo and his colleagues describe in a paper published Wednesday in the journal Proceedings of the Royal Society Bthe unusual jaw of Tanyka era simply part of your evolutionary “package”. And there are eight more similar fossils confirming this.

A Tanyka (“jaw” in the Guarani language, from local indigenous communities) was a very ancient vertebrate with four limbs: one tetrapod.

Currently, there are examples of animals with four legs among birdsmammals, reptiles and amphibians, but all trace back to a single lineage of tetrapods, the so-called stem tetrapods.

Over time, these tetrapods separated into two groups: one that started laying eggs on land and another that continued to lay eggs in water. THE Tanykahowever, remained firmly in the “camp” of stem tetrapods.

“A Tanyka comes from an ancient lineage that we didn’t know had survived until this time,” said Pardo. The paleontologist compares it to the current platypus. Almost all living mammals reproduce through birth, but the first mammals laid eggs. The platypus has maintained this ability over millions of years, becoming a species of “exception” among mammals.

And then there’s Tanyka’s mouth. The lower teeth did not point upwards — were oriented sideways. At the same time, the section of the jaw that, in humans, faces the tongue was oriented toward the roof of the mouth.

These surfaces were still covered by tiny teethknown as denticles, which transformed the inclined jaw into a kind of grinding surface.

“Based on the teeth, we think the Tanyka was herbivorous and ate plants, at least part of the time,” he said. Juan Carlos Cisnerosco-author of the study and paleontologist at the Federal University of Piauí, in Brazil.

This just reinforces the uniqueness of the animalas the vast majority of trunk tetrapods were strictly carnivorous.

“The denticles in the lower jaw would be rubbing against similar teeth in the upper part of the mouth.teeth would have to scrape togetherin a way that should create a relatively unique feeding mode,” added Pardo.

Based on these details, its closest evolutionary relatives, and its riverine habitat, the study authors believe that Tanyka would likely resemble a salamander measuring approximately 0.9 meters long, with a more elongated snout. But, at least for now, determining what it looks like is, to a large extent, an exercise in guesswork.

“We found these isolated jaws, and they are really strange and very distinctive,” he said. Ken Englishcurator of paleomammology at the Field Museum and co-author of the study.

“But, until we found one of those jaws attached to a skull or other bones that are unequivocally associated with the jaw, we cannot say with certainty that the other bones that were nearby were of Tanyka.” Until then, Tanyka’s jaw alone has already enough, and plenty, to raise eyebrows.

It was already, in its own time, a living fossil, and it was an evolutionary oddity, paleontologists say: the Tanyka amnicolarecently discovered in Brazil, had a jaw that is a real puzzle.

There are many animals that today are considered “living fossils”. This is the case, for example, that long considered extinct, it has continued to swim in the Earth’s oceans since the time of the dinosaurs.

Also the horseshoe crabs which were from Covid-19, appear in the fossil record hundreds of millions of years ago. And many sharks seem practically unchanged in relation to their ancestors from the Cretaceous period.

But, although the Tanyka amnicola was last seen around 275 million years ago, was already, in his own time, a living fossil.

It was also a creature extremely strange. So strange, in fact, that paleontologists came to think they had in front of them a anomaly ancient when they discovered the first jaw of this animalwhich has an appearance similar to a salamanderin a dry riverbed near the Amazon rainforest in Brazil.

“The jaw has a strange twist that drove us crazy trying to understand what it was. We thought about it for years, wondering if it was some kind of deformation”, he recalled. Jason Pardopaleontologist at the Field Museum in Chicago, in a statement published on .

But as Pardo and his colleagues describe in a paper published Wednesday in the journal Proceedings of the Royal Society Bthe unusual jaw of Tanyka era simply part of your evolutionary “package”. And there are eight more similar fossils confirming this.

A Tanyka (“jaw” in the Guarani language, from local indigenous communities) was a very ancient vertebrate with four limbs: one tetrapod.

Currently, there are examples of animals with four legs among birdsmammals, reptiles and amphibians, but all trace back to a single lineage of tetrapods, the so-called stem tetrapods.

Over time, these tetrapods separated into two groups: one that started laying eggs on land and another that continued to lay eggs in water. THE Tanykahowever, remained firmly in the “camp” of stem tetrapods.

“A Tanyka comes from an ancient lineage that we didn’t know had survived until this time,” said Pardo. The paleontologist compares it to the current platypus. Almost all living mammals reproduce through birth, but the first mammals laid eggs. The platypus has maintained this ability over millions of years, becoming a species of “exception” among mammals.

And then there’s Tanyka’s mouth. The lower teeth did not point upwards — were oriented sideways. At the same time, the section of the jaw that, in humans, faces the tongue was oriented toward the roof of the mouth.

These surfaces were still covered by tiny teethknown as denticles, which transformed the inclined jaw into a kind of grinding surface.

“Based on the teeth, we think the Tanyka was herbivorous and ate plants, at least part of the time,” he said. Juan Carlos Cisnerosco-author of the study and paleontologist at the Federal University of Piauí, in Brazil.

This just reinforces the uniqueness of the animalas the vast majority of trunk tetrapods were strictly carnivorous.

“The denticles in the lower jaw would be rubbing against similar teeth in the upper part of the mouth.teeth would have to scrape togetherin a way that should create a relatively unique feeding mode,” added Pardo.

Based on these details, its closest evolutionary relatives, and its riverine habitat, the study authors believe that Tanyka would likely resemble a salamander measuring approximately 0.9 meters long, with a more elongated snout. But, at least for now, determining what it looks like is, to a large extent, an exercise in guesswork.

“We found these isolated jaws, and they are really strange and very distinctive,” he said. Ken Englishcurator of paleomammology at the Field Museum and co-author of the study.

“But, until we found one of those jaws attached to a skull or other bones that are unequivocally associated with the jaw, we cannot say with certainty that the other bones that were nearby were of Tanyka.” Until then, Tanyka’s jaw alone has already enough, and plenty, to raise eyebrows.