choanoflagellate
A group of free-living unicellular and colonial flagellate eukaryotes considered to be the closest living relatives of animals. Technical term used in biology.
Choanoflagellates are considered the closest unicellular relatives of animals.
Compound of 襟 (eri, 'collar') + 鞭毛虫 (benmōchū, 'flagellate'), referring to the collar of microvilli surrounding the flagellum characteristic of these organisms.