noun
Paleoheterodonta
Taxonomic term for a subclass of bivalve molluscs. Used in biological and paleontological contexts.
古異歯類には、ドブガイやカラスガイなどが含まれる。
Paleoheterodonta includes species such as the swan mussel and the cockscomb pearl mussel.
Composed of 古 (old), 異 (different), 歯 (tooth), and 類 (group/class), referring to the ancient and distinct hinge teeth of these bivalves. The exact derivation is uncertain; the term is a modern taxonomic coinage.