Fossil Lycophytes

Lepidodendron (All rights reserved) S. Dengler, used with permission
Lepidodendron sp.—mature (left) and immature (right) reconstruction. (All rights reserved) S. Dengler, used with permission

Fossils of lycophytes are among the most common plant fossils reported in Oklahoma; one fossil, called Stigmaria, represents about half of all plant fossils brought to the Museum for identification by our staff.  Lycophyte fossils may be found in rocks that were deposited during both the Pennsylvanian and Permian Periods, but are most commonly associated with coal seams (above, below, or in) where preservation occurred as impressions, compressions, casts and molds.

Lepidodendron (Knorria)

Lepidodendron is the name (= form-genus) for impressions of the outer bark of large arborescent lycophytes. Lepidodendron is also the name that paleobotanists use to refer to the biological genus for entire plant, including all of its individual parts. Lepidodendron grew to over 100 feet (30 meters) tall and preferred the wetter, but not wettest areas in swamps.

Lepidodendron is recognized by the diamond-shaped pattern of leaf scars that spiral around the trunk of the tree; each scar being generally taller than wide.

During the life of the tree, the outer bark of Lepidodendron trees would be shed revealing the layer beneath This inner bark layer displayed a different pattern and is given a separate and distinct name, called Knorria, when found in the fossil record.