Halkieria Evangelista. The halkieriids are a group of fossil organisms.Their eponymous genus is Halkieria, which has been found on almost every continent in Lower to Mid Cambrian deposits, forming a large component of the small shelly fossil assemblages.
Skull of Dunkleosteus Terrelli (prehistoric fish) Don't go swimming in the Devonian sea. One of the scariest creatures ever to live in the ocean, this Devonian fish could grow up to 33 feet long, had an armored face, and likely had one of the strongest bites in history! It used a beak-like mouth instead of teeth to devour its prey. It was one of the largest of the Placoderms, a group of armored fish that are now extinct.