An epiphytacean-Girvanella (Cyanobacteria) symbiosis from the Cambrian (Series 3, Drumian) of North Greenland (Laurentia)

The widespread Cambrian calcareous cyanobacterium Girvanella is described in symbiotic association with a new epiphytacean, Orpikania freucheni gen. et sp. nov. (Microproblematica), from the Ekspedition Bræ Formation (Cambrian Series 3, Drumian Stage) of Freuchen Land, North Greenland. The phosphatized assemblages preserve dendrites of the epiphytacean forming a supporting framework for discrete climbing filaments of Girvanella lianiformis sp. nov. that are firmly attached to their host with holdfasts. Elevation of the slender Girvanella filaments on the framework of the dendrite potentially enhanced their phototactic movement towards the light. Filaments in the co-occurring Girvanella pituutaq sp. nov. are regularly twisted together into a rope-like form which may have assisted elevation above its substrate.