Wikipedia
Camuropiscidae
Camuropiscidae is a family of mostly small, bullet or spindle-shaped arthrodire placoderms from the Late Devonian. With the exception of the snub-nosed Simosteus, camuropiscid placoderms are characterized by an elongated, tubular snout. The entire family is restricted to the Frasnian Gogo Reef Formation of Australia.
The camuropiscids' elongated snouts and bullet-shaped bodies are thought to be adaptions for hydrodynamic streamlining. They are assumed to have been mid-water predators of shrimp-like crustaceans.