Calamite
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Calamites Temporal range: Carboniferous to Early Permian |
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| A range of Calamites specimens, illustrating the different appearance of fossils preserved under different taphonomic modes. | |
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Pteridophyta |
| Class: | Equisetopsida |
| Order: | Equisetales |
| Family: | Calamitaceae |
| Genus: | Calamites |
| Species | |
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Calamites carinatus |
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Calamites carinatus
Calamites cistii
Calamites cruciatus
Calamites goeppertii
Calamites multiramis
Calamites ramosus
Calamites rectangulus
Calamites sachsei
Calamites schuetzeiformis
Calamites schulzii
Calamites sickowii
Calamites suckowi
Calamites undulatus
Calamites is a genus of extinct arborescent (tree-like) horsetails to which the modern horsetails (genus Equisetum) are closely related. Unlike their herbaceous modern cousins, these plants were medium-sized trees, growing to heights of more than 30 meters (100 feet). They were components of the understories of coal swamps of the Carboniferous Period (around 360 to 300 million years ago).
A number of organ taxa have been identified as part of a united organism, which has inherited the name Calamites in popular culture. Calamites correctly refers only to casts of the stem of Carboniferous/Permian sphenophytes, and as such is a form genus of little taxonomic value. There are two forms of casts, which can give mistaken impressions of the organisms. The most common is an internal cast of the hollow (or pith-filled) void in the centre of the trunk. This can cause some confusion: firstly, it must be remembered that a fossil was probably surrounded with 4-5 times its width in (unpreserved) vascular tissue, so the organisms were much wider than the internal casts preserved. Further, the fossil gets narrower as it attaches to a rhizoid, a place where one would expect there to be the highest concentration of vascular tissue (as this is where the peak transport occurs). However, because the fossil is a cast, the narrowing in fact represents a constriction of the cavity, into which vascular tubes encroach as they widen.
Further organ genera belonging to sphenophytes include:
The trunks of Calamites had a distinctive segmented, bamboo-like appearance and vertical ribbing. The branches, leaves and cones were all borne in whorls. The leaves were needle-shaped, with up to 25 per whorl.
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Wikipedia