Calamophyton Temporal range: | |
---|---|
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Division: | Pteridophyta (?) |
Class: | † Cladoxylopsida |
Order: | † Pseudosporochnales |
Family: | † Hyeniaceae |
Genus: | † Calamophyton R.Kräusel & H.Weyland, 1925 |
Species | |
|
Calamophyton is an extinct genus of tree, or "tree-sized plant", [1] that was extant in the Middle Devonian period. As of 2024, a well-preserved fossilized forest of Calamophyton trees discovered in Somerset, England, represents the earliest-known forest. [2]
The genus was established in 1926 from specimens collected by R. Kräusel & H. Weyland, in Hardberg and Kirberg, Rhineland, Germany, who identified the type species Calamophyton primaevum. [3] A second species, C. renieri, was described by Suzanne Leclercq in Belgium in 1940; a third, C. bicephalum, also found in Belgium, by Leclercq and H. Andrews in 1960; [3] and a fourth, C. forbesii, in the Mapleton Sandstone, Maine, United States, by James M. Schopf in 1964. [4] It has since been suggested that C. primaevum and C. bicephalum are conspecific. [5] All specimens date to the Middle Devonian, some 385 to 395 million years ago. [3] [4] [6]
The genus has been described as having an unusual—and unusually complex—morphology, superficially palm-like. Specimens are between 0.8 metres (2+1⁄2 feet) [1] and 4 metres (13 ft) in height. [7] Like other cladoxylopsids, the tree trunk was hollow, and composed of multiple interconnected longitudinal strands of vascular woody material (xylem). [8] [9] As the xylem bundles grew in diameter, they would split apart from one another near the apex of the trunk, thus limiting the overall height. [8] [10] The trunk apex was domed rather than tapered, and like the trunk base, wider than the midsection. Some trunks may have forked. [1]
Calamophyton did not have leaves, but rather small branches consisting of twig-like structures [7] that grew only at or near the trunk apex, and which were the site of photosynthesis for the plant. [7] As the trunk grew, the lower branches would be shed; a mature tree might in the course of its growth shed as many as 700 to 800 branches, [11] creating a thick carpet of decaying twigs on the ground below, with few understory plants observed. Where other cladoxylopsids shed their branches smoothly, Calamophyton left small stubs behind on the trunk. [11]
The root system consisted of several hundred to more than a thousand strap-like roots of 2–6 millimetres (0.079–0.24 inches) in diameter and, for the larger trunks, in excess of 300 millimetres (12 inches) in length. [lower-alpha 1] The roots were approximately straight, undivided, and extended almost directly downward into the soil. The fossil record indicates that in spite of their small diameter, they were stiff and hardy. [1] Calamophyton reproduced not by seeds, but via spores, one of several characteristics suggesting a relationship with the Pteridophyta. [7]
In March 2024, paleontologists reported the discovery of an intact fossil forest of Calamophyton trees in the Hangman Sandstone Formation at Minehead, Somerset, England. As of the reporting date, it is the earliest forest yet discovered. [2] [7] [10] At an age of 390 million years, the forest pre-dates the previously oldest-known example—a root system probably belonging to Archaeopteris , discovered in 2009 near Cairo, New York [12] —by about four million years. [2] [7] [10] In the Middle Devonian period, when the Calamophyton forest was alive, the Somerset region would have been adjacent to Germany and Belgium. [2] [7]
According to Christopher Berry, one of the scientists involved in the discovery, the preservation of the Calamophyton fossil forest, with trees still in the positions where they grew, allows a direct, and unprecedented, examination of the local ecology. [7] Of particular interest is the sedimentary system, in which the plants are seen capturing and stabilizing fluvial sediments. [7]
Pinus strobus, commonly called the eastern white pine, northern white pine, white pine, Weymouth pine (British), and soft pine is a large pine native to eastern North America. It occurs from Newfoundland, Canada, west through the Great Lakes region to southeastern Manitoba and Minnesota, United States, and south along the Appalachian Mountains and upper Piedmont to northernmost Georgia and perhaps very rarely in some of the higher elevations in northeastern Alabama. It is considered rare in Indiana.
Lepidodendron is an extinct genus of primitive lycopodian vascular plants belonging the order Lepidodendrales. It is well preserved and common in the fossil record. Like other Lepidodendrales, species of Lepidodendron grew as large-tree-like plants in wetland coal forest environments. They sometimes reached heights of 50 metres, and the trunks were often over 1 m (3.3 ft) in diameter. They are often known as "scale trees", due to their bark having been covered in diamond shaped leaf-bases, from which leaves grew during earlier stages of growth. However, they are correctly defined as arborescent lycophytes. They thrived during the Carboniferous Period, and persisted until the end of the Permian around 252 million years ago. Sometimes erroneously called "giant club mosses", the genus was actually more closely related to modern quillworts than to modern club mosses. In the form classification system used in paleobotany, Lepidodendron is both used for the whole plant as well as specifically the stems and leaves.
Araucarioxylon arizonicum is an extinct species of conifer that is the state fossil of Arizona. The species is known from massive tree trunks that weather out of the Chinle Formation in desert badlands of northern Arizona and adjacent New Mexico, most notably in the 378.51 square kilometres Petrified Forest National Park. There, these trunks are locally so abundant that they have been used as building materials.
Asteroxylon is an extinct genus of vascular plants of the Division Lycopodiophyta known from anatomically preserved specimens described from the famous Early Devonian Rhynie chert and Windyfield chert in Aberdeenshire, Scotland. Asteroxylon is considered a basal member of the Lycopsida.
Stigmaria is a form taxon for common fossils found in Carboniferous rocks. They represent the underground rooting structures of arborescent lycophytes such as Sigillaria and Lepidodendron under the order Lepidodendrales.
The Eifelian is the first of two faunal stages in the Middle Devonian Epoch. It lasted from 393.3 ± 1.2 million years ago to 387.7 ± 0.8 million years ago. It was preceded by the Emsian Stage and followed by the Givetian Stage.
In the geological timescale, the Middle Devonian epoch occurred during the Devonian period, after the end of the Emsian age.
The progymnosperms are an extinct group of woody, spore-bearing plants that is presumed to have evolved from the trimerophytes, and eventually gave rise to the gymnosperms, ancestral to acrogymnosperms and angiosperms. They have been treated formally at the rank of division Progymnospermophyta or class Progymnospermopsida. The stratigraphically oldest known examples belong to the Middle Devonian order the Aneurophytales, with forms such as Protopteridium, in which the vegetative organs consisted of relatively loose clusters of axes. Tetraxylopteris is another example of a genus lacking leaves. In more advanced aneurophytaleans such as Aneurophyton these vegetative organs started to look rather more like fronds, and eventually during Late Devonian times the aneurophytaleans are presumed to have given rise to the pteridosperm order, the Lyginopteridales. In Late Devonian times, another group of progymnosperms gave rise to the first really large trees known as Archaeopteris. The latest surviving group of progymnosperms is the Noeggerathiales, which persisted until the end of the Permian.
Wattieza was a genus of prehistoric trees that existed in the mid-Devonian that belong to the cladoxylopsids, close relatives of the modern ferns and horsetails. The 2005 discovery in Schoharie County, New York, of fossils from the Middle Devonian about 385 million years ago united the crown of Wattieza to a root and trunk known since 1870. The fossilized grove of "Gilboa stumps" discovered at Gilboa, New York, were described as Eospermatopteris, though the complete plant remained unknown. These fossils have been described as the earliest known trees, standing 8 m (26 ft) or more tall, resembling the unrelated modern tree fern.
The cladoxylopsids are an extinct group of plants related to ferns and sphenopsids.
Gilboa Fossil Forest, New York, United States, is a petrified forest and one of the oldest known forests. Located near the Gilboa Dam in Schoharie County, New York, the region is home to tree trunks from the Devonian period. The fossils, some of the only survivors of their type in the world, are believed to have been from one of the first forests on Earth, and was part of the Earth's afforestation. Paleobotanists have been interested in the site since the 1920s when construction work for a water supply project found several large, vertical fossilized stumps. Some of these remain on display at the Gilboa Dam site and the New York Power Authority Blenheim-Gilboa Visitor's Center in Schoharie County and at the New York State Museum.
Psilophyton is a genus of extinct vascular plants. Described in 1859, it was one of the first fossil plants to be found which was of Devonian age. Specimens have been found in northern Maine, USA; Gaspé Bay, Quebec and New Brunswick, Canada; the Czech Republic; and Yunnan, China. Plants lacked leaves or true roots; spore-forming organs or sporangia were borne on the ends of branched clusters. It is significantly more complex than some other plants of comparable age and is thought to be part of the group from within which the modern ferns and seed plants evolved.
Zosterophyllum was a genus of Silurian-Devonian vascular land plants with naked branching axes on which usually kidney-shaped sporangia were arranged in lateral positions. It is the type genus for the group known as zosterophylls, thought to be part of the lineage from which modern lycophytes evolved. More than 20 species have been described.
Sawdonia is an extinct genus of early vascular plants, known from the Upper Silurian to the Lower Carboniferous. Sawdonia is best recognized by the large number of spikes (enations) covering the plant. These are vascular plants that do not have vascular systems in their enations. The first species of this genus was described in 1859 by Sir J. William Dawson and, was originally attributed to the genus Psilophyton. He named this plant Psilophyton princeps. In 1971 Francis Hueber proposed a new genus for this species due to its "Divergent technical characters from the generic description for Psilophyton." The holotype used for description is Dawson Collection Number 48, pro parte, Museum Specimen Number 3243. Sir J. William Dawson Collection, Peter Redpath Museum, McGill University, Montreal, Quebec, Canada.
Lepidodendrales or arborescent lycophytes are an extinct order of primitive, vascular, heterosporous, arborescent (tree-like) plants belonging to Lycopodiopsida. Members of Lepidodendrales are the best understood of the fossil lycopsids due to the vast diversity of Lepidodendrales specimens and the diversity in which they were preserved; the extensive distribution of Lepidodendrales specimens as well as their well-preservedness lends paleobotanists exceptionally detailed knowledge of the coal-swamp giants’ reproductive biology, vegetative development, and role in their paleoecosystem. The defining characteristics of the Lepidodendrales are their secondary xylem, extensive periderm development, three-zoned cortex, rootlike appendages known as stigmarian rootlets arranged in a spiralling pattern, and megasporangium each containing a single functional megaspore that germinates inside the sporangium. Many of these different plant organs have been assigned both generic and specific names as relatively few have been found organically attached to each other. Some specimens have been discovered which indicate heights of 40 and even 50 meters and diameters of over 2 meters at the base. The massive trunks of some species branched profusely, producing large crowns of leafy twigs; though some leaves were up to 1 meter long, most were much shorter, and when leaves dropped from branches their conspicuous leaf bases remained on the surface of branches. Strobili could be found at the tips of distal branches or in an area at the top of the main trunk. The underground organs of Lepidodendrales typically consisted of dichotomizing axes bearing helically arranged, lateral appendages serving an equivalent function to roots. Sometimes called "giant club mosses", they are believed to be more closely related to extant quillworts based on xylem, although fossil specimens of extinct Selaginellales from the Late Carboniferous also had secondary xylem.
A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, photosynthesis takes place here, stores nutrients, and produces new living tissue. The stem can also be called halm or haulm or culms.
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. In wider definitions, the taller palms, tree ferns, bananas, and bamboos are also trees.
Sartilmania is a genus of extinct vascular plants of the Early Devonian. Fossils were found on the Sart Tilman campus of the University of Liège, Belgium.
Tetraxylopteris is a genus of extinct vascular plants of the Middle to Upper Devonian. Fossils were first found in New York State, USA. A second species was later found in Venezuela.
The Silurian-Devonian Terrestrial Revolution, also known as the Devonian Plant Explosion (DePE) and the Devonian explosion, was a period of rapid colonization, diversification and radiation of land plants and fungi on dry lands that occurred 428 to 359 million years ago (Mya) during the Silurian and Devonian periods, with the most critical phase occurring during the Late Silurian and Early Devonian.