Stunning Cryptozoon Wisconsin Ordovician Stromatolites
Time: Lower Ordovician (495 million years old)
mm by 145 mm (maximum)
Oneota Formation, Oconto County, Wisconsin
Coming from the Lower Ordovician Oneota Formation, this eminently
aesthetic specimen is some 495 million years old, from a time that
Prokaryotic life forms no longer had exclusive use of earth's shorelines.
Concomitantly, the earth’s coastal habitats had markedly reduced
stromatolite reefs, compared with those of the Proterozoic. It has
been cut across the growth plane of the colony making it easy to
see where the common name bullseye is derived.
this time in geological history, microbial communities consisted
of complex consortia of both prokaryotic and eukaryotic forms with
diverse metabolic needs, and competition for resources and differing
motility among them made for an intriguing microcosm of interacting
raw rock from which this stunning specimen was cut was acquired
some two years ago from a location that was situated at the top
of an anticline that has since been demolished, making this an extremely
limited form. This remarkable specimen is appropriate for display,
teaching or research, representing primitive prokaryotic life responsible
for forming the atmosphere that we breathe today. Stromatolites
have persisted to the modern day in such places as Shark Bay, Australia
where they continue their billions of years old lifestyle.
click stromatolites pictures