Abstract
A scombrid fossil was found from the early Middle Miocene Korematsu Formation in the Bihoku Group in Tsujita, Niimi City, Okayama Prefecture, Japan. The fossil is the anterior part of the left premaxilla that belongs to the tribe Scomberonorini and probably belongs to the genus Acanthocybium, because the teeth are set in a row without space between each tooth. However, the teeth are larger than those of Acanthocybium solandri and the form of ascending process is similar to those of Scomberomorus species.
