Tanyka

Tanyka (lit. 'jaw') is an extinct genus of amphibious early stem-tetrapod known from the Early Permian (Kungurian age) Pedra de Fogo Formation of Brazil. The genus contains a single species, Tanyka amnicola, known from several mandibular remains. It is one of the few Gondwanan stem-tetrapods known to have survived into the Permian. The lower jaw is strongly twisted, with extensive fields of teeth, likely allowing it to process aquatic plants or small invertebrates.

Prior to the discovery of Tanyka, the prevailing view on tetrapod evolution was that the early stem-groups were suddenly replaced by temnospondyl amphibians and amniotes following the Carboniferous rainforest collapse at the end of the Moscovian age (~307 million years ago). However, Tanyka and other late-surviving tetrapods from the Early Permian, like Gaiasia jennyae (described in 2024), demonstrate that the replacement of stem-tetrapods by later temnospondyls and amniotes was more complex than previous hypotheses implied.