{{Short description|Extinct genus of tree}} {{Automatic taxobox | image = Calamophyton reconstruccion.jpg | image_caption = | fossil_range = {{Fossil range|Middle Devonian}} | taxon = Calamophyton | authority = R.Kräusel & H.Weyland, 1925 | subdivision_ranks = Species | subdivision = {{Species list |C. primaevum |<small>(Kräusel & Weyland)</small> |C. renieri |<small>(Leclercq)</small> |C. bicephalum |<small>(Leclercq & Andrews)</small> |C. forbesii |<small>(Schopf)</small> }} }}
'''''Calamophyton''''' is an extinct genus of tree, or "tree-sized plant",<ref name="geisen_berry_2013">{{cite journal |last1=Geisen |first1=Peter |last2=Berry |first2=Christopher M. |title=Reconstruction and Growth of the Early Tree ''Calamophyton'' (Pseudosporochnales, Cladoxylopsida) Based on Exceptionally Complete Specimens from Lindlar, Germany (Mid-Devonian): Organic Connection of ''Calamophyton'' Branches and Duisbergia Trunks |journal=International Journal of Plant Sciences |date=May 2013 |volume=174 |issue=4 |pages=665–686 |doi=10.1086/669913 |url=https://dx.doi.org/10.1086/669913 |access-date=18 March 2024}}</ref> 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.<ref name="devlin">{{cite news |last1=Devlin |first1=Hannah |author-link=Hannah Devlin |title=World's oldest fossilised trees discovered along Devon and Somerset coast |url=https://www.theguardian.com/science/2024/mar/06/worlds-oldest-fossilised-trees-discovered-along-devon-and-somerset-coast |access-date=17 March 2024 |newspaper=The Guardian |publisher=Guardian News & Media Limited |date=7 March 2024}}</ref>
== Discovery == 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''.<ref name="leclercq_andrews_feb1960_pp1-2">{{cite journal |author1-last=Leclercq |author1-first=Suzanne |author1-link=Suzanne Leclercq |author2-last=Andrews |author2-first=Henry N. Jr.|author2-link=Henry Nathaniel Andrews |title=''Calamophyton bicephalum'', a New Species from the Middle Devonian of Belgium |journal=Annals of the Missouri Botanical Garden |date=Feb 1960 |volume=47 |issue=1 |page=2 |doi=10.2307/2394614 |jstor=2394614 |url=https://www.jstor.org/stable/2394614|url-access=subscription }}</ref> 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;<ref name="leclercq_andrews_feb1960_pp1-2"/> and a fourth, ''C. forbesii'', in the Mapleton Sandstone, Maine, United States, by James M. Schopf in 1964.<ref name="digitalmaine">{{cite web |author1-last=Kasper |author1-first=Andrew E. Jr |author2-last=Gensel |author2-first=Patricia G. |author2-link=Patricia G. Gensel |author3-last=Forbes |author3-first=William H. |last4=Andrews |first4=Henry N. Jr. |title=Plant Paleontology in the State of Maine - A Review |url=https://digitalmaine.com/cgi/viewcontent.cgi?article=1048&context=mgs_publications |website=Digital Maine |publisher=Maine Geological Survey |access-date=18 March 2024}}</ref> It has since been suggested that ''C. primaevum'' and ''C. bicephalum'' are conspecific.<ref name="leclercq1969">{{cite journal |last1=Leclercq |first1=Suzanne |title=''Calamophyton primaevum'': The Complex Morphology of Its Fertile Appendage |journal=American Journal of Botany |date=Aug 1969 |volume=56 |issue=7 |pages=773–781 |doi=10.2307/2440597 |jstor=2440597 |url=https://www.jstor.org/stable/2440597 |access-date=7 April 2024|url-access=subscription }}</ref> All specimens date to the Middle Devonian, some {{Mya|385|395}}.<ref name="leclercq_andrews_feb1960_pp1-2"/><ref name="digitalmaine"/><ref name="ucmp">{{cite web |title=Introduction to the Cladoxylopsida |url=https://ucmp.berkeley.edu/plants/cladoxylopsida/cladoxylopsida.html |publisher=University of California Museum of Paleontology |access-date=7 April 2024}}</ref>
== Description == The genus has been described as having an unusual—and unusually complex—morphology, superficially palm-like. Specimens are between {{convert|0.8|m|ft|abbr=off|frac=2}}<ref name="geisen_berry_2013"/> and {{convert|4|m}} in height.<ref name="ralls"/> Like other cladoxylopsids, the tree trunk was hollow, and composed of multiple interconnected longitudinal strands of vascular woody material (xylem).<ref name="cardiff_23oct2017">{{cite web |title=World's oldest and most complex trees |url=https://www.cardiff.ac.uk/news/view/981090-worlds-oldest-and-most-complex-trees |website=Cardiff University |access-date=18 March 2024 |date=23 October 2017}}</ref><ref name="fairon2000">{{cite journal |last1=Fairon-Demaret |first1=Muriel |last2=Berry |first2=Christopher M. |title=A Reconsideration of Hyenia elegans Kräusel et Weyland and Hyenia `complexa' Leclercq: Two Middle Devonian Cladoxylopsids from Western Europe |journal=International Journal of Plant Sciences |date=May 2000 |volume=161 |issue=3 |page=473 |doi=10.1086/314267 |url=https://www.jstor.org/stable/10.1086/314267 |access-date=21 April 2024}}</ref> 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.<ref name="cardiff_23oct2017"/><ref name="newatlas">{{cite web |last1=Irving |first1=Michael |title=Strange trees in world's oldest forest ripped themselves apart to grow |url=https://newatlas.com/science/oldest-forest-prototype-trees-calamophyton/ |website=New Atlas |access-date=18 March 2024 |date=13 March 2024}}</ref> The trunk apex was domed rather than tapered, and like the trunk base, wider than the midsection. Some trunks may have forked.<ref name="geisen_berry_2013"/>
''Calamophyton'' did not have leaves, but rather small branches consisting of twig-like structures<ref name="ralls"/> that grew only at or near the trunk apex, and which were the site of photosynthesis for the plant.<ref name="ralls">{{cite web |last1=Ralls |first1=Eric |title=World's 'newest' oldest forest, recently discovered, is full of ''Calamophyton'' trees |url=https://www.earth.com/news/worlds-newest-oldest-forest-recently-discovered-is-full-of-calamophyton-trees/ |website=Earth.com |access-date=18 March 2024 |date=7 March 2024}}</ref> 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,<ref name="geosociety_23feb2024">{{cite journal |last1=Davies |first1=Neil S. |last2=McMahon |first2=William J. |last3=Berry |first3=Christopher M. |title=Earth's earliest forest: fossilized trees and vegetation-induced sedimentary structures from the Middle Devonian (Eifelian) Hangman Sandstone Formation, Somerset and Devon, SW England |journal=Journal of the Geological Society |date=23 February 2024 |issue=4 |doi=10.1144/jgs2023-204|url=https://www.lyellcollection.org/doi/abs/10.1144/jgs2023-204 |access-date=14 April 2024|doi-access=free }}</ref> 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.<ref name="geosociety_23feb2024"/>
The root system consisted of several hundred to more than a thousand strap-like roots of {{convert|2|-|6|mm|sigfig=2|abbr=off}} in diameter and, for the larger trunks, in excess of {{convert|300|mm|inch|abbr=off}} in length.{{efn|Root dimensions given here are based on the specimens of up to 2 metres in height.<ref name="geisen_berry_2013"/>}} 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.<ref name="geisen_berry_2013"/> ''Calamophyton'' reproduced not by seeds, but via spores, one of several characteristics suggesting a relationship with the Pteridophyta.<ref name="ralls"/>
== Earliest-known forest == 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.<ref name="devlin"/><ref name="ralls"/><ref name="newatlas"/> 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<ref name="barras">{{cite web |last1=Barras |first1=Colin |title=Scientists have discovered the world's oldest forest—and its radical impact on life |url=https://www.science.org/content/article/scientists-have-discovered-world-s-oldest-forest-and-its-radical-impact-life |website=Science |publisher=American Association for the Advancement of Science |access-date=18 March 2024 |date=19 December 2019}}</ref>—by about four million years.<ref name="devlin"/><ref name="ralls"/><ref name="newatlas"/> In the Middle Devonian period, when the ''Calamophyton'' forest was alive, the Somerset region would have been adjacent to Germany and Belgium.<ref name="devlin"/><ref name="ralls"/>
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.<ref name="ralls"/> Of particular interest is the sedimentary system, in which the plants are seen capturing and stabilizing fluvial sediments.<ref name="ralls"/>
== Footnotes == {{Notelist}}
== References == {{Reflist|2}} {{Taxonbar|from1=Q1026227}}
Category:Middle Devonian plants Category:Plants described in 1925 Category:Prehistoric plant genera