noun ac·ri·tarch \ˈa-kri-ˌtärk\

Definition of acritarch

  1. :  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

Origin and Etymology of acritarch

Greek akritos uncertain (from a- + kritos, verbal of krinein to decide) + archē beginning — more at certain, arch-

First Known Use: 1963

Learn More about acritarch

Seen and Heard

What made you want to look up acritarch? Please tell us where you read or heard it (including the quote, if possible).