Kawasphenodon

Kawasphenodon is an extinct genus of sphenodontian reptile, known from the Late Cretaceous and Paleogene of Patagonia in South America. The type species, K. expectatus, was described in 2005 from jaw fragments found in late Campanian aged sediments in the Los Alamitos Formation, the jaw when complete was estimated to be 11 cm long, making it among the largest known sphenodontians.[1] A second species, K. peligrensis, around 1/3 the size of the type species, was described in 2014 also from jaw fragments in early Paleocene (Danian) sediments of the Salamanca Formation, making it the youngest known definitive representative of Rhynchocephalia outside of New Zealand.[2] In the original description, it was found to be a member of Sphenodontidae, in other subsequent analyses it was found to be a member of Opisthodontia. A 2020 analysis of rhyncocephalian relationships found it to be the closest known relative of the tuatara, with an estimated divergence in the Early Cretaceous.[3] Like most other rhynchocephalians, the teeth are acrodont, with a deep dentary, and it probably had an omnivorous habit.[2]

Kawasphenodon Temporal range: Campanian–Danian PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Rhynchocephalia
Suborder:	Sphenodontia
Genus:	†Kawasphenodon Apesteguía 2005
Type species
Kawasphenodon expectatus Apesteguía 2005
Other species
Kawasphenodon peligrensis Apesteguía et al. 2014