Scombriformes are an incredibly diverse order of ray-finned fish including Mackerel, Tuna, Barracuda, Kingfish, Cutlassfish and Swordfish.

Scombriformes evolved during the Paleocene but enjoyed significant species diversification during the Eocene of which the London Clay showcases well.

Most Scombriformes are pelagic fish (open-ocean) and are highly adapted for speed with streamlined bodies, optimised to reduce drag. Most Scombriformes are the apex predators in their ecological niches.

This artistic reconstruction shows a large Duplexdens macropomus hunting a shoal of Halecopsis insignis.