Fossil Finds
PLACODERMS
Armor-Plated Fish of the Devonian
BY JOSEPH “PALEOJOE” KCHODL
As ayoung boy growing up in fossil-rich western New York, I would spend untold hours walking the rocky outcrops of the Niagara Escarpment, the shore of an ancient Silurian Sea, collecting hundreds of marine fossils including Brachiopods and Crinoids. The joy of discovery spurred me to learn more. Who knew my road would lead me to Michigan? Some 40 years later in northern Michigan, I happened upon a fossil I had never seen. Little did I know of the wonder and amazement of finding armor-plated fish with a hammer and chisel.
PLACODERM TYPES
Placoderms are some of the best-known fish of the ancient seas because of their hard dermal plates. “Placo” means plate and “derm” means skin. These fish had hard plates on their head section and the part of the thorax just behind the head. They also sported large flat bony plates. Since soft tissue generally does not fossilize, these plates are usually the only evidence we are able to find. They were a group of now-extinct prehistoric jawed fish that were abundant in ancient seas.