Bizarre Prehistoric Creature with Twisted Jaw and Sideways Teeth Discovered

Tanyka amnicola, a 275-million-year-old tetrapod, was already a 'living fossil' in its time

Published on Mar. 4, 2026

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Paleontologists have described a newly identified prehistoric species called Tanyka amnicola, which lived 275 million years ago and had a bizarre twisted jaw with sideways-facing teeth. Despite predating the dinosaurs, T. amnicola was already an evolutionary relic, belonging to an ancient lineage of tetrapods that had mostly disappeared by that time.

Why it matters

The discovery of T. amnicola provides a rare glimpse into the diversity of tetrapod life during the Permian period, long before the rise of dinosaurs. The creature's unique jaw and feeding adaptations suggest it occupied a distinct ecological niche, shedding light on the structure and dynamics of ancient Gondwanan ecosystems.

The details

Researchers identified the new species from nine fossilized lower jawbones recovered from a dry riverbed in northeastern Brazil. Analysis of the jawbones revealed that they were twisted, with the teeth pointing outward to the sides rather than upward as seen in most other tetrapods. The inner surface of the jawbone was also rotated upward and covered in small, tooth-like structures called denticles, suggesting T. amnicola had a unique feeding mechanism, possibly adapted to munch on small invertebrates or plant material.

  • The fossils of Tanyka amnicola date back to the Permian period, approximately 275 million years ago.

The players

Tanyka amnicola

A newly identified species of prehistoric tetrapod that lived 275 million years ago and had a bizarre twisted jaw with sideways-facing teeth.

Jason Pardo

A research associate at the Field Museum in Chicago and the lead author of the study describing Tanyka amnicola.

Ken Angielczyk

A curator of paleomammalogy at the Field Museum and a co-author of the study on Tanyka amnicola.

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What they’re saying

“Tanyka is from an ancient lineage that we didn't know survived to this time, and it's also just a really strange animal.”

— Jason Pardo, Field Museum research associate (Field Museum)

“The jaw has this weird twist that drove us crazy trying to figure it out. We were scratching our heads over this for years, wondering if it was some kind of deformation. But at this point, we've got nine jaws from this animal, and they all have this twist, including the really, really well-preserved ones. So it's not a deformation, it's just the way the animal was made.”

— Jason Pardo, Field Museum research associate (Field Museum)

“Tanyka is telling us about how this community actually worked, how it was structured, and who was eating what.”

— Ken Angielczyk, Curator of paleomammalogy, Field Museum (Field Museum)

What’s next

Researchers plan to continue studying the fossils of Tanyka amnicola to learn more about its anatomy, ecology, and evolutionary relationships to other tetrapods.

The takeaway

The discovery of Tanyka amnicola, a bizarre 275-million-year-old tetrapod with a twisted jaw and sideways teeth, provides a rare glimpse into the diversity of life during the Permian period, long before the rise of dinosaurs, and highlights the persistence of ancient evolutionary lineages.