Photo: Vitor Silva
Paleontologists have uncovered an unusual fossil creature with a twisted jaw and sideways-pointing teeth. According to Live Science, this species lived on Earth 275 million years ago and has been described as a “living fossil.”
The new species, named Tanyka amnicola, is an ancient member of the tetrapods—a large group of four-limbed vertebrates that today includes reptiles, birds, mammals, and amphibians.
Although T. amnicola lived before the dinosaurs, it was already an evolutionary relic during the Permian period. Many of the earliest tetrapod lineages had already gone extinct by then, but the lineage to which Tanyka belonged persisted while other four-limbed vertebrates diversified.
“Tanyka belongs to an ancient tetrapod line we didn’t know existed, and it’s truly a very strange animal. In being a surviving stem-tetrapod even after newer, modern tetrapods appeared, it’s somewhat reminiscent of a platypus. At its time, it was a living fossil,” said Jason Pardo, lead author of the study and a researcher at the Field Museum in Chicago.
Scientists identified the new species from nine fossilized lower jaws, each about 15 centimeters long, found in the dry riverbed in northeastern Brazil. While the jaws were sufficient to determine it was a new species, much about the animal remains unknown.
Based on related species, T. amnicola may have resembled a salamander and reached lengths of roughly 91 centimeters. The type of rock in which the fossils were found suggests it lived in lakes and likely had aquatic habits.
Jaw analysis revealed that the teeth pointed outward rather than upward, as in most other tetrapods.
“There’s a strange bend in the jaw that baffled us for years as we tried to understand it. We wondered if it was a deformity, but with nine jaws showing the same bend, including very well-preserved specimens, we now know it’s a natural feature,” Pardo explained.
The inner jaw surface was covered with small tooth-like structures called denticles, forming a grinding surface. This suggests the animal had a relatively unique way of feeding.
Researchers believe T. amnicola ate small invertebrates and possibly plant material, which is unusual since most early tetrapods were primarily predators.
