Heteronectes chaneti is a fossil fish which has been identified as an early relative of the flatfish, and as a transitional fossil. In a typical modern flatfish, the head is asymmetric with both eyes on one side of the head. In Heteronectes, the transition from the typical symmetric head of a vertebrate is incomplete, with one eye positioned near the top of the head, very similar, but less so than its Italian relative, Amphistium. Heteronectes is found in the early to middle Eocene of France.