{"id":1458,"date":"2026-03-04T00:12:50","date_gmt":"2026-03-04T00:12:50","guid":{"rendered":"https:\/\/owspakistan.com\/?p=1458"},"modified":"2026-03-04T10:21:11","modified_gmt":"2026-03-04T10:21:11","slug":"salamander-ancestor-weird-fossil","status":"publish","type":"post","link":"https:\/\/owspakistan.com\/?p=1458","title":{"rendered":"Bizarro salamander ancestor was an evolutionary oddball"},"content":{"rendered":"
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There are quite a few animals considered \u201cliving fossils\u201d in today\u2019s world. Once thought extinct, the prehistoric coelacanth<\/a> has continuously swam through Earth\u2019s oceans since the time of the dinosaurs. Horseshoe crabs<\/a> exist in fossil records<\/a> dating back hundreds of millions of years. Even many sharks<\/a> look virtually unchanged from their Cretaceous Era ancestors. But although Tanyka amnicola<\/em> was last seen about 275 million years ago, it was already a living fossil in its own time.<\/p>\n

It was also an extremely<\/em> strange creature. So strange, in fact, that paleontologists initially thought they were looking at an ancient aberration when they discovered the first jawbone of this salamander-esque creature in a dry riverbed near the Amazon rainforest in Brazil.<\/p>\n

\"Tanyka
A Tanyka jawbone, with rock hammer for scale, found in the Brazil. Credit: Ken Angielczyk \/ Field Museum
<\/em> <\/figcaption><\/figure>\n

\u201cThe 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,\u201d recalled Jason Pardo<\/a>, a paleontologist at Chicago\u2019s Field Museum.<\/p>\n

As Pardo and his colleagues detail in a study published today in the journal Proceedings of the Royal Society B<\/em><\/a>, Tanyka<\/em>\u2019s odd jaw was simply part of its evolutionary package. And they have eight other similar fossil specimens to prove it.<\/p>\n

Tankya<\/em> (\u201cjaw\u201d in the local Indigenous Guaran\u00ed language) was an incredibly early four-legged vertebrate, or tetrapod. Present-day examples of four-legged animals are found across birds, mammals, reptiles, and amphibians, but they all trace back to a single lineage called stem tetrapods. Eventually, stem tetrapods separated into two groups\u2014one that laid eggs on land, and another that laid them in water. Tankya<\/em>, however, firmly remained in the \u201cstem tetrapod\u201d camp.<\/p>\n

\u201cTanyka<\/em> is from an ancient lineage that we didn\u2019t know survived to this time,\u201d said Pardo.<\/p>\n

He likens it to the present-day platypus. Almost every living mammal reproduces through live births, but the first examples laid eggs. The platypus retained its egg-laying abilities over millions of years, making a bit of a mammalian oddity.<\/p>\n

And then there is Tanyka<\/em>\u2019s mouth. The bottom teeth didn\u2019t face upward\u2014they pointed to either side instead. Meanwhile, the section of jaw that faces the tongue in humans was oriented toward the roof of the mouth. These surfaces were also covered in tiny teeth known as denticles that turned the angled jaw into a grinding surface.<\/p>\n

\"Fossil
Fossil showing the denticles on the jaw, forming a cheese-grater-like surface that may have been used for grinding plant matter. Credit: Ken Angielczyk \/ Field Museum<\/em> <\/figcaption><\/figure>\n

\u201cBased on its teeth, we think that Tanyka<\/em> was a herbivore, and that it ate plants at least some of the time,\u201d said Juan Carlos Cisneros, a study co-author and paleontologist at Brazil\u2019s Federal University of Piau\u00ed.<\/p>\n

This only adds to the animal\u2019s uniqueness, since the vast majority of stem tetrapods were strictly carnivorous.<\/p>\n

\u201cWe expect the denticles on the lower jaw were rubbing up against similar teeth on the upper side of the mouth. The teeth would have been rasping against each other, in a way that\u2019s going to create a relatively unique way of feeding,\u201d added Pardo.<\/p>\n

Based on these details, its closest evolutionary relatives, and its river habitat, the study\u2019s authors believe Tanyka<\/em> likely resembled a three-foot-long salamander sporting a lengthier snout. But at least for now, determining what it looked like is mostly guesswork.<\/p>\n

\u201cWe found these jaws in isolation, and they\u2019re really weird, and they\u2019re very distinctive,\u201d said Field Museum paleomammalogy curator and study co-author Ken Angielczyk. \u201cBut until we find one of those jaws attached to a skull or other bones that are definitively associated with the jaw, we can\u2019t say for sure that the other bones we find near it belong to Tanyka<\/em>.\u201d<\/p>\n

Until then, Tanyka<\/em>\u2019s jawbone alone is still more than enough to raise eyebrows.<\/p>\n

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