noun
- An extinct armored fish of the Paleozoic era, characterized by a bony plated skeleton and jaws.
Usage: paleontology; scientific
Examples
- Placoderms were among the earliest jawed vertebrates to appear in the fossil record.
- The placoderm's heavy armor plates protected it from predators in ancient seas.
- Scientists study placoderm fossils to understand the evolution of fish and vertebrate jaws.
- Unlike modern fish, placoderms had a rigid body covered in bony plates rather than scales.
- The extinction of placoderms at the end of the Devonian period marked a major shift in marine life.