Wakinosaurus satoi is an extinct genus theropod from early Cretaceous Japan, known solely from the middle section of a tooth.

Wakinosaurus satoi by teratophoneus-d4y6kal

Discovery and naming[]

n 1990 the ice hockey player Masahiro Sato in Fukuoka found the tooth of a theropod. The same year Yoshihiko Okazaki first reported on the find. In 1992 Okazaki named the type species, Wakinosaurus satoi. The generic name refers to the Wakino Subgroup of the Kwanmon Group, of which the Sengoku Formation is a member. The specific name honours Sato.


The holotype is KMNH VP 000,016, a single damaged tooth, the crown of which must have been about seven centimetres long. Its base length is 32.9 millimetres (1.30 in), its base width 10.4 millimetres (0.41 in). It has about thirty serrations per five millimetres.

Wakinosaurus was initially described as a megalosaurid but is today considered a nomen dubium and an indeterminate neotheropod. The holotype tooth is similar to a leaf with fine cutting serrations on both edges and according to Okazaki, it is similar to those of "Prodeinodon" kwangshiensis, which is also a dubious tooth taxon. In 2020, it was suggested that Wakinosaurus may represent a basal carcharodontosaurid theropod similar to Acrocanthosaurus.