the modern remaining prototherian lines are the Australian and New Guinean monotremes, egg-laying mammals now represented by the grub- and shrimp-eating platypus (Ornithorhyncus) and ant-eating echidna (Tachyglossus and Zaglossus).
belonging or pertaining to the subclass prototheria of monotremes
Hyphenation
be·long·ing or pertaining to the sub·class prototheria of monotremes