Seen as one of the first forms of life, the Ediacaran age bacterial mats where most probably constructed of oxygen producing cyanobacteria. Is rare to find a form of life dating from 550 mil y before present.
Ediacaran Bacterial Mat/Cyanobaterian mat
Ediacaran (551 - 538 mil y.)
200 x 115 mm - 8" x 4 5/8"