Overview
- Tanyka amnicola is formally named as an archaic stem tetrapod dating to about 275 million years ago in a peer-reviewed paper.
- Researchers identified the species from nine roughly 15-centimeter lower jaws recovered from a dry riverbed in northeastern Brazil’s Pedra de Fogo Formation.
- The lower jaws are consistently twisted so the teeth point outward, and the inner surface is rotated upward and carpeted with denticles that form a grinding surface.
- The anatomy suggests a relatively unusual feeding mode, with authors inferring consumption of small invertebrates or possibly some plant material, unlike most carnivorous stem tetrapods.
- Only isolated jaws are known, so reconstructions of body shape and size (estimated up to about 3 feet) remain provisional, though sediments indicate a freshwater lake or river habitat in Gondwana.