STROMATOLITES

Also known as: Algal mounds

Informal group: Monera

Age range: Precambrian-Recent

Found in OK: Ordovician-Silurian rocks, especially in Arbuckle Mountains

Stromatolites are actually mounds of mud that have been preserved. Very few stromatolites actually contain fossils of the organisms that built them. Stromatolites accumulate because blue-green algae (actually bacteria-like organisms) produce a sticky film that catches mud and silt, forming a thin layer. Over time, layer upon layer builds up forming these mounds.

Geologic Time
Time Scale
Cretaceous
Pennsylvanian
Mississippian
Devonian
Silurian
Ordovician

Fossil Images
Common Cretaceous Fossils
Common Pennsylvanian Fossils
Common Mississippian Fossils
Common Devonian Fossils
Common Silurian Fossils
Common Ordovician Fossils