Callipteryx

Callipteryx is an extinct genus of prehistoric marine percomorph fish that lived during the early Eocene. It is the only known member of the extinct family Callipterygidae. It contains a single species, C. speciosus, known from the famous Monte Bolca site of Italy.
It was initially thought to have been a relative of weeverfishes. However, a more recent analysis suggests that it cannot be classified within any of the known percomorph groups. It may potentially be an indeterminate perciform.