Bizarre Prehistoric Creature With 'Twisted' Jaw Discovered in Brazil

The newly identified species, Tanyka amnicola, is rewriting textbooks on early tetrapod evolution.

Mar. 16, 2026 at 6:36pm

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Researchers excavating in Brazil have discovered the fossilized remains of a bizarre prehistoric creature with a uniquely twisted jaw, which they have identified as a new species called Tanyka amnicola. This 275-million-year-old animal is challenging long-held assumptions about when certain ancient creatures disappeared from the planet, as it appears to have persisted long after similar species went extinct.

Why it matters

The discovery of Tanyka amnicola, with its strange jaw anatomy unlike any other known tetrapod, is forcing scientists to rethink their understanding of early animal evolution. This 'living fossil' provides a glimpse into a more experimental stage of tetrapod development, when nature was still trying out different designs for how a mouth could function.

The details

The researchers initially found a single twisted jawbone during excavations, assuming it must be a deformity or the remains of a fish. But after uncovering nine more fossils with the same unique jaw structure, they realized this was a natural anatomical feature of a previously unknown species. Tanyka's lower jaw twisted outward, with teeth pointing sideways rather than inward, and it had small grinding teeth called denticles that likely allowed it to chew tough plant material and small invertebrates.

  • The Tanyka amnicola fossils date back approximately 275 million years.
  • The fossils were discovered during excavations in Brazil.

The players

Tanyka amnicola

A newly identified prehistoric tetrapod species that lived around 275 million years ago, characterized by its uniquely twisted jaw structure.

Martha Richter

A coauthor of the study describing Tanyka amnicola, who initially thought the fossils might belong to a fish before realizing the true nature of the creature.

Jason Pardo

The lead author of the study describing Tanyka amnicola, who noted that the team was "driven crazy" trying to figure out the purpose of the animal's strange jaw.

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What they’re saying

“At first, we wondered if these fossils might be the remains of a fish. It was only once the fossils were properly prepared in the lab that the true nature of Tanyka was clearly revealed to us.”

— Martha Richter, Coauthor

“It's a really strange animal, and the weird twist in the jaw drove us crazy trying to figure it out. But nine jaws we've found have this twist, including the really well-preserved ones, so it's not a deformation. It's just the way this animal was.”

— Jason Pardo, Lead author

What’s next

The researchers believe there may be additional Tanyka amnicola fossils in the area that could provide more clues about the creature's full body shape and evolutionary relationships.

The takeaway

The discovery of Tanyka amnicola, a 'living fossil' that persisted long after similar species went extinct, highlights how much we still have to learn about the early stages of tetrapod evolution. This bizarre creature with its uniquely twisted jaw challenges our assumptions and suggests the fossil record may hold many more evolutionary surprises waiting to be uncovered.