n.extinct primitive toothed bird with a long feathered tail and three free clawed digits on each wing
英汉双解大词典
archaeornis/ˌɑːkɪˈɔːnɪs/
1.
N（名词）
an extinct primitive Jurassic bird, formerly placed in the genus Archaeornis but now thought to be a species of archaeopteryx 古鸟; 生存于侏罗纪时代的已灭绝鸟类，后被认为是始祖鸟的一类