noun see: certain Date: 1963 any of a group of fossil one-celled marine planktonic organisms of uncertain and possibly various taxonomic affinities held to represent the earliest known eukaryotes
ACRITARCH
Meaning of ACRITARCH in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012