Twisted-Jaw Tetrapod from Gondwana Illuminates Early Plant-Eating Life

Researchers describe Tanyka amnicola, a 275-million-year-old stem tetrapod known from seven to nine jawbones found in Brazil’s Pedra de Fogo Formation. The jaws are twisted with outward-facing teeth and a denticle-covered inner surface, indicating a grinding mechanism for plant matter and suggesting early herbivory among stem tetrapods. The discovery places this “living fossil” in Gondwana’s Permian ecosystems and helps fill gaps in the fossil record, though the full skeleton remains unknown and may have measured up to about 0.9 meters in length.