Tartuosteus

The branchials of Tartuosteus form a boomerang-like shape, while the center of the body dips deeply into a keel-like protrusion.

[1] These branchials are so large that when measured for the amount of lift they can produce, its lift-to-drag ratio is comparable to that of a jet airplane.

This lift force would provide Tartuosteus with an efficient cruising ability while reducing maneuverability.

This suggests that Tartuosteus was effective at exploiting widely distributed food sources, possibly plankton in the water column, or at escaping predation.

[2] Tartuosteus has a somewhat convoluted taxonomic past, with species being lumped into and out of the genus and others being declared based on poor remains.