Marpolia has been interpreted as a cyanobacterium, but also resembles the modern cladophora

Cladophora

Cladophora is a genus of reticulated filamentous Ulvophyceae . The genus Cladophora contains many species that are very hard to tell apart and classify, mainly because of the great variation in their appearances, which is affected by habitat, age and environmental conditions...

n green algae. It is known from the Middle Cambrian Burgess shale

Burgess Shale

The Burgess Shale Formation, located in the Canadian Rockies of British Columbia, is one of the world's most celebrated fossil fields, and the best of its kind. It is famous for the exceptional preservation of the soft parts of its fossils...

and Early Cambrian deposits from the Czech Republic. It comprises a dense mass of entangled, twisted filaments. It may have been free-floating or grown on other objects, although there is no evidence of attachment structures.