Ediacaran - Biota

Biota

The animal fossil record from this period is sparse, possibly because animals had yet to evolve hard shells, which make for easier fossilization. The Ediacaran biota include the oldest definite multicellular organisms with tissues, and the most common types resemble segmented worms, fronds, disks, or immobile bags. They bear little resemblance to modern lifeforms, and their relationship even with the later lifeforms of the Cambrian explosion is difficult to interpret. More than 100 genera have been described, and well known forms include Arkarua, Charnia, Dickinsonia, Ediacaria, Marywadea, Onega, Pteridinium, and Yorgia.

In addition, there are unverified claims of "footprints" - tracks made by legged organisms thought to resemble arthropods or legged worms. The significance of these finds awaits their publication.

Read more about this topic:  Ediacaran