Pleuronectiformes are the bottom-dwelling order of ray-finned fish which contain commercially valuable species such as Flatfish, Halibut, Turbot, Flounder, Sole and Plaice (to name a few). Evolving during the Late Palaeocene and diversifying during the Eocene, these fish all share the characteristic of asymmetry with both eye located on the same side of the fish in adult life.