Xenophyophorida

Xenophyophorida are an order of protozoa. They range in size of up to about 2 millimeters and look like tiny fan- or branch-like structures. At maturity, they are single-celled but multi-nucleated. Three genera in the order exist: Psammetta, Stannoma, and Stannophyllum, but taxonomic classification is indefinite due to the lack of information about the organisms.

Source
Richard P. Hall, "Xenophyophorida", in AccessScience@McGraw-Hill, http://www.accessscience.com, DOI 10.1036/1097-8542.751900, last modified: April 10, 2000. Accessed March 3, 2006.