What are five prehistoric small marine creatures?
Trilobites ranged in size from about half an inch to around two
feet in length. Haikouicthys, one of the earliest known fish, was
about an inch long. Ammonites ranged in size from around 9 inches
to some species as large as 6.5 feet. Anamolocaris was a huge apex
predator for its time, but by modern standards wasn't very large,
only measuring three to six feet long. Rudists, a type of bivalve
that was so common during the Cretaceous, piles of them formed
reefs. They ranged from a few centimeters to over a meter in
length, depending on the type.