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Lycopod

Lycopods (also called lycopsids or lycophytes) represent one of the oldest division of vascular plants, dating back to the Silurian Period (about 425 million years ago). They reproduce by generating spores.

Whereas modern lycopods barely reach one foot in height, Carboniferous-age lycopods were tree-like, growing up to 100 feet tall and having trunks upwards of 3 feet in diameter. They thrived in wet, swampy areas. Leaves originated directly from the outer surfaces of trunks as the lycopods grew, but living leaves were concentrated near the tree tops. Fossils of lycopod trunks bear a pattern of leaf scars, which in some species resemble scales, as on a snakeskin. The name of a common lycopod, Lepidodendron, means "scale tree." Roots of lycopod trees look much alike and are assigned the form genus name, Stigmaria.

In Ohio, fossil remains of lycopods are found in rocks that span Late Devonian through Late Carboniferous (Pennsylvanian) time. They are known from the Upper Devonian Ohio Shale and are common in Upper Carboniferous coals and sandstones. Lycopods contributed much of the organic matter forming the coal deposits in Upper Carboniferous rocks. Called kettlebottoms by miners, fossil stumps of lycopods present an instability hazard in the roofs of some coal mines.

The genera and/or species listed are representative only; species found in Ohio are too numerous to list here. For identification of genera and species, refer to Bulletin 70: Fossils of Ohio (see Additional Information).

Additional Information

Bulletin 54: Ohio Fossils (out of print, superseded by Bulletin 70)

Bulletin 70: Fossils of Ohio – To order, contact the Geologic Records Center