SPHENOPSIDS

Also known as: Horsetails, Scouring rushes

Informal group: Land plants

Age range: Devonian-Recent

Found in OK: Pennsylvanian and Permian rocks; most common in eastern Oklahoma

Living plants known as "horsetails" or "scouring rushes" belong to the genus Equisetum. Equisetum, contains about 66 species and is the only modern representative of an ancient plant group called "Sphenopsids." Sphenopsids were very common on the edges of coal swamps during the Pennsylvanian. Three common Oklahoma plant fossils belong to this group: Calamites, Annularia and Asterophyllites. These are the trunk and leaves of a tree that grew to a height of several meters (over 10 feet).

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