Amphistium

Amphistium is a genus of 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 Amphistium, the transition from the typical symmetric head of a vertebrate is incomplete, with one eye placed near the top of the head.

Heteronectes is similar fossil.