noun
prototherians
A zoological term referring to the subclass Prototheria, which includes monotremes such as the platypus and echidna. Used in academic or scientific contexts.
原獣類にはカモノハシやハリモグラが含まれる。
Prototherians include the platypus and echidna.
A compound of 原 (gen, 'primitive') and 獣類 (jūrui, 'mammals'), literally 'primitive mammals'. The term is a direct translation of the taxonomic name Prototheria.