Sphenophyte fossils may be found in rocks that were deposited during both the Pennsylvanian and Permian Periods as impressions, compressions, casts and molds.
Fossils of sphenophytes are among the most common plant fossils reported in Oklahoma and Calamites represents about half of all plant fossils brought to the museum for identification by our staff.


Calamites sp.PTC-4; Sphenophyte; Pennsylvanian; Locality unknown; CC BY-NC-ND 4.0
Calamites sp.


Calamites sp.OPC 3551-7765; Sphenophyte; Middle Pennsylvanian (Desmoinesian); Krebs Group, Savanna Formation; Pittsburg County, Oklahoma; CC BY-NC-ND 4.0
Calamites sp.


Calamites sp.OPC 3026-1757; Sphenophyte; Middle Pennsylvanian (Desmoinesian); Cabaniss Group, Senora Formation; Okmulgee County, Oklahoma; CC BY-NC-ND 4.0
Calamites sp.


Annularia sp.OPC 3004-1456; Sphenophyte; Middle Pennsylvanian (Desmoinesian); Skiatook Group, Seminole Formation, Seminole Coal roof shale; Tulsa County, Oklahoma; CC BY-NC-ND 4.0
Annularia sp.


Annularia sp.OPC 3019-1481; Sphenophyte; Middle Pennsylvanian (Desmoinesian); Skiatook Group, Coffeyville Formation; Tulsa County, Oklahoma; CC BY-NC-ND 4.0
Annularia sp.


Annularia sp.OPC 3067-6445; Sphenophyte; Middle Pennsylvanian (Desmoinesian); Krebs Group, Boggy Formation, Secor Coal roof shale; McIntosh County, Oklahoma; CC BY-NC-ND 4.0
Annularia sp.


Asterophyllites sp.OPC 3019-14006; Sphenophyte; Middle Pennsylvanian (Desmoinesian); Skiatook Group, Coffeyville Formation; Tulsa County, Oklahoma; CC BY-NC-ND 4.0
Asterophyllites sp.


Asterophyllites sp.OPC 3019-1480; Sphenophyte; Middle Pennsylvanian (Desmoinesian); Skiatook Group, Coffeyville Formation; Tulsa County, Oklahoma; CC BY-NC-ND 4.0
Asterophyllites sp.


Sphenophyllum sp.OPC 3005-263; Sphenophyte; Middle Pennsylvanian (Desmoinesian); Skiatook Group, Seminole Formation; Tulsa County, Oklahoma; CC BY-NC-ND 4.0