The keichoisaurus was a semi aquatic lizard that lived in the falang formation and existed during the trassic
A eurypterid aka a sea scorpion was marine predator that extisted from the ordovician to permian period and filled many niches some Sea scorpions had stingers that they used to slice and dice, some had pincers that they used to rip apart pray, and sift through substrate.
Knightia was a fish that was related to herring that existed in the Green River Formation
The Cockerllites was a fish that was related to perch
A trilobites was a prehistoric aurthropod that existed from the cambrian to permian. Trilobites filled many niches some trilobites were predators, some trilobites were scavengers, and some were even parasites.