|Calamopleurus cylindricus (Agassiz, 1841) / Collection of David Murphy|
They are fossil relics, the sole surviving species of the order Amiiformes. Although bowfins are highly evolved, they are often referred to as primitive fishes and living fossils as they retain many of the morphologic characteristics of their ancestors.
This specimen is from Calamopleurus cylindricus of the Family Amiidae. He was found in Lower Cretaceous outcrops of the Santana Formation in the Araripe Basin UNESCO Global Geopark of northeastern Brazil.