This is a very detailed CYLINDROPHYLLUM coral from the Potter Farm Formation of Michigan.
These creatures are animals and are commonly called corals and sometimes horn corals They are tiny colonial filter feeders.
These are some of the most abundant fossils found in certain deposits. They are considered some of the reef builders of the ancient Devonian Seas.
They had tiny tentacles that filtered the water for food. Each creature lived in the indentations. They often made up huge colonies.
These are presented in this handsome glass topped leatherette case that is 3 1/4 inches by 4 1/4 inches.
These are the specimens you will receive.