Does these look like lichens to you? According to Gregory Retallack, they should.
Yesterday, Nature published an article by Retallack that makes a radical claim: the Ediacaran Biota (635-542 mya) of bizarre creatures that preceded the Cambrian Explosion were not pneumatic semi-mobile marine animals, but instead sessile land-dwelling lichens and protists living high and very much dry on land.
For those of us raised on pictures and dioramas of puffy Ediacaran animals ensconced happily on the seafloor, this is a bit of a shocker. Although scientists in the past have suggested that they *might* be giant marine protists, Retallack seems to be alone in carrying the lichen torch.
His analysis of the rock surrounding the fossils suggests to him the soil of dry land, and his analysis of cross sections of these fossils to him suggests lichen rootlets and biological soil crusts. Lichens today are symbiotic associations of fungi and algae.
You’ve probably seen a few in your time plastered to rocks, tombstones, or tree bark. Biological soil crusts are loose associations of cyanobacteria, algae, fungi, lichens, mosses familiar to those of us who live in the west*. They may represent some sort of proto-lichens or lichen incubators.