Fossil Plants

Following are Pennsylvanian plants collected in in the Cahaba coal field near a "town" called Marvel north of Montevalo, AL and south-southwest of Birmingham, AL. The trick is to collect in the bedding shale on either side of a coal seam, or in the spoil pile left over after strip or shaft mining. The strip pits where these were collected are not accessible by regular car, and were it not for the help of one of the locals with a 4x4, we would have gone home empty-handed.

The plants represented here are Calamites, a giant horsetail (sphenophyte), and its foliage, assigned to the genus Annularia; Stigmaria, the rhizome of a lepidodendroid club moss (lycophyte); and Sphenopteris, a seed fern (pteridosperm).

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	Calamites sp. Note the "bamboo" like appearance of the stem, with numerous parallel veins and a jointed stem. Along the joint, one can see two radial scars where smaller branches split off of the main stem. While the genus Calamites is extinct, modern horsetails still live today, but at generally under a meter tall, they do not attain the tree-like proportions (estimated up to 20 meters or 65 feet) of their extinct relatives.
Annularia sp. The genus Annularia is used to designate detached foliage most likely attributable to a sphenophyte like Calamites, if not the actual foliage of Calamites itself.
	Stigmaria sp. The genus Stigmaria is assigned to the detached rhizomes (root systems) of lepidodendroid lycophytes (Lepidodendron, Sigillaria), which, unlike modern lycophytes not reaching heights of more than a meter, could attain heights of 50 meters (160 feet). Note on the specimen the circular scars where the roots were attached.

Sphenopteris hoeninghausii. Here are three specimens total of Sphenopteris, a member of the Pteridospermales, or seed ferns. Seed ferns, rather than reproducing by spores as true ferns do, reproduced by seeds, a trait that has caused them to be classified as gymnosperms along with ginkgoes, cycads, pines and the like. There are no known living seed ferns today.

The two smaller Sphenopteris specimens give a better view of the finer detail of a Sphenopteris frond, while the larger one gives an overview of the frond structure ... apparently this larger frond was bent doubled over itself during preservation (or perhaps a second frond overlayed the first).

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