| Calamites Fossil range: Carboniferous - early Permian |
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 A range of Calamites specimens, illustrating the different appearance of fossils preserved under different taphonomic modes. The Carboniferous is a geologic period and system that extends from the end of the Devonian period about 359 The Permian is a geologic period and system that extends from 299
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See text. Plants are living Organisms belonging to the kingdom Plantae. A fern is any one of a group of about 20000 Species of Plants classified in the phylum or division Pteridophyta, also known as Filicophyta Equisetopsida, or Sphenopsida, is a class of Plants with a fossil record going back to the Devonian. The Equisetales is an order of pteridophytes with only one living genus Equisetum (horsetails Calamitaceae is an extinct family of plants related to the modern Horsetail. |
Calamites is a genus of extinct arborescent (tree-like) horsetails to which the modern horsetails (genus Equisetum) are closely related. In Biology and Ecology, extinction is the cessation of existence of a Species or group of taxa. Equisetum is a genus of Vascular plants that reproduce by spores rather than seeds Equisetum is a genus of Vascular plants that reproduce by spores rather than seeds Unlike their herbaceous modern cousins, these plants were medium-sized trees, growing to heights of more than 30 meters (100 feet). A(n herb (ˈhɝb or /ˈɝb/ see pronunciation differences) is a plant that is valued for qualities such as medicinal properties flavor scent or the like They were components of the understories of coal swamps of the Carboniferous period. The Carboniferous is a geologic period and system that extends from the end of the Devonian period about 359
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Taphonomy
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 organims. 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 Arthropitys (stems which are preserved in a mineralised form), Astromyelon (permineralised rhizomes, distinguished from Arhtropitys by the absence of a carinal canal), Annularia and Asterophylites (form genera of leaf-whorls which are embarrassingly paraphyletic).
Anatomy
The trunks of Calamites had a distinctive segmented, bamboo-like appearance and vertical ribbing. Bamboo is a group of Woody perennial Evergreen Plants in the True grass family Poaceae, subfamily The branches, leaves and cones were all borne in whorls. The leaves were needle-shaped, with up to 25 per whorl.
Their trunks produced secondary xylem, meaning they were made of wood. In Vascular plants xylem is one of the two types of transport tissue Phloem being the other The vascular cambium of Calamites was unifacial, producing secondary xylem towards the stem center, but not secondary phloem. The vascular cambium is a Lateral meristem in the Vascular tissue of plants In Vascular plants phloem is the living tissue that carries organic Nutrients (known as photosynthate particularly Sucrose, a sugar to
The stems of modern horsetails are typically hollow or contain numerous elongated air-filled sacs. Calamites was similar in that its trunk and stems were hollow, like wooden tubes. When these trunks buckled and broke, they could fill with sediment. Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of This is the reason pith casts of the inside of Calamites stems are so common as fossils. FOSSIL is a standard protocol for allowing serial communication for Telecommunications programs under the DOS Operating system.
Reproduction
Calamites reproduced by means of spores, which were produced in small sacs organized into cones. They are also known to have possessed massive, underground rhizomes, which allowed for the production of clones of one tree. In Botany, a rhizome is a horizontal stem of a Plant that is usually found underground often sending out Roots and Shoots Cloning in Biology is the process of producing populations of genetically-identical individuals that occurs in nature when organisms such as Bacteria, Insects This is the only group of trees of their period known to have a clonal habit. This type of asexual reproduction would allow them to spread quickly into new territory, in addition to aiding in anchoring them firmly in the unstable ground along rivers and in newly deposited delta sediments. Asexual reproduction is a form of reproduction which does not involve Meiosis, Ploidy reduction or Fertilization. Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of The rhizomes of Calamites look quite similar to the stems in most cases, but have nodes that get progressively closer together as they get out approach the apical area (the growth tip that spreads outward through the soil).
Different forms
Calamites come in a variety of different "form genera". One type, Calamites suckowi, is distinguishable from other Calamites forms by its prominent, swollen nodes and relatively wide-spaced longitudinal ribs. Another example, Calamites cisti, has much smaller nodes and the ribs are typically closer together.
In addition, the distance between successive node lines on a Calamites suckowi specimen is typically much wider than the diameter. In other forms like Calamites cisti, the opposite is true or the specimen is just slightly wider than the diameter.
However, the value of these form taxa is limited. The distance between nodes, for example, is highly variable, and an intercalary meristem means that this distance varied as the organisms grew.
Extinction and classification
The genus Calamites has been placed in the plant division Equisetophyta (formerly known as Sphenophyta) and family Calamitaceae. Equisetopsida, or Sphenopsida, is a class of Plants with a fossil record going back to the Devonian. They finally became extinct in the Lower Permian, a time which, however, also saw the origin of the family Equisetaceae, to which the only living sphenophyte genus Equisetum belongs. The Permian is a geologic period and system that extends from 299 Equisetum is a genus of Vascular plants that reproduce by spores rather than seeds Equisetum is a genus of Vascular plants that reproduce by spores rather than seeds
See also
References
- How large are the giant horsetails?
- Sphenophyta: Fossil Record
- Stewart, W. Archaeopteris is an Extinct genus of tree-like plants with Fern -like leaves N. Paleobotany and the Evolution of Plants. Cambridge University Press, Cambridge (1983).
- Davis, Paul and Kenrick, Paul. Fossil Plants. Smithsonian Books (in association with the Natural History Museum of London), Washington, D. C. (2004). ISBN 1-58834-156-9
External links
- Photo-(High Res, Close-up): Fossil stem, Showing "leaflet" whorl w/ vertical ribbing; Article – "Newhay Quarry," Lancashire
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