micrallantoid,a.rare.|maɪkrəˈlæntɔɪd| [f. micro- + allantoid.] Having a small allantois. (Cf. megallantoid, mesallantoid.) 1877W. Turner Hum. Anat. ii. 869 Milne Edwards has grouped them [the Rodentia, Insectivora, Cheiroptera, Quadrumana, and Man] together in a Micrallantoid legion.