noun
ratites
Zoological term for the group of flightless birds with a flat breastbone, including ostriches, emus, kiwis, etc. Often contrasted with 走鳥類 (sōchōrui, 'running birds').
See also: 走鳥類
平胸類にはダチョウやエミューが含まれる。
Ratites include ostriches and emus.
平胸類は飛
Ratites are known as a group of flightless birds.