Agathoxylon (also known by the synonyms Dadoxylon and Araucarioxylon[3]) is a form genus of fossil wood, including massive tree trunks. Although identified from the late Palaeozoic to the end of the Mesozoic,[4]Agathoxylon is common from the Carboniferous to Triassic.[5]Agathoxylon represents the wood of multiple conifer groups, including both Araucariaceae[6] and Cheirolepidiaceae,[7] with late Paleozoic and Triassic forms possibly representing other conifers or other seed plant groups like "pteridosperms".[8]
Description
Agathoxylon were large trees that bore long strap-like leaves and trunks with small, narrow rays.[5] Often the original cellular structure is preserved as a result of silica in solution in the ground water becoming deposited within the wood cells. This mode of fossilization is termed permineralization.
Systematics
As a genus, Dadoxylon was poorly defined, and apart from Araucariaceae, has been associated with fossil wood as diverse as Cordaitales,[9]Glossopteridales and Podocarpaceae. Furthermore, it may be the same form genus as Araucarioxylon, hence the usage Dadoxylon (Araucarioxylon).[10] The genus Agathoxylon, classified under the familyAraucariaceae,[11] has nomenclatural priority over the genera Araucarioxylon and Dadoxylon.[12][13][8]
Several Dadoxylon species, such as D. brandlingii and D. saxonicum have been identified as Araucarites.[14]D. arberi and D. sp.1 were synonymised with the glossopterid species Australoxylon teixterae and A. natalense, respectively; while D. sp. 2 was transferred to Protophyllocladoxylon.
Agathoxylon pseudoparenchymatosum (Gothan 1908) Pujana et al. 2014 [=Araucarioxylon chilense, A. kerguelense, A. novaezeelandii, A. pseudoparenchymatosum, Dadoxylon kaiparaense, D. kergulense, D. pseudoparenchymatosum]: Santa Marta Formation, Antarctica
Agathoxylon santacruzense Kloster and Gnaedinger 2018: La Matilde Formation, Argentina
Agathoxylon santalense (Sah & Jain): La Matilde Formation, Argentina
^Torrey, R. E. (1923). "The comparative anatomy and phylogeny of the Coniferales Part 3: Mesozoic and Tertiary coniferous woods". Proceedings and Transactions of the Royal Society of Canada. 3. Vol. 6. Memoirs of the Boston Society of Natural History. pp. 38–103.
^Giraud, Bernadette (1991). "Les espèces du genre Dadoxylon depuis 1962: Leur répartition et leur évolution du Permien à la fin du Mésozoïque". Review of Palaeobotany and Palynology. 67 (1–2): 13–39. Bibcode:1991RPaPa..67...13G. doi:10.1016/0034-6667(91)90014-T.
^ abMencl, Václav; Matysová, Petra; Sakala, Jakub (2009). "Silicified wood from the Czech part of the Intra Sudetic Basin (Late Pennsylvanian, Bohemian Massif, Czech Republic): Systematics, silicification and palaeoenvironment". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 252 (3): 269. doi:10.1127/0077-7749/2009/0252-0269.
^ Pujana, R. R., Wilf, P., & Gandolfo, M. A. (2020). Conifer wood assemblage dominated by Podocarpaceae, early Eocene of Laguna del Hunco, central Argentinean Patagonia. PhytoKeys, 156, 81–102. https://doi.org/10.3897/phytokeys.156.54175
^D. Vogellehner (1965). "Untersuchungen zur Anatomie und Systematik der Verkieselten Holzer aus dem Frankischen und Sunthuringischen Keuper". Erlanger Geologische Abhandlungen. 59: 1–76.
^P.M. Oesterlen (1990). "The geology of the Dande West area (western Cabora Bassa Basin) - a preliminary report". Annals of the Zimbabwe Geological Survey. 14: 12–20.
^D. Love (1997). "The geology of the Chirundu area, Zambezi Valley". Annals of the Zimbabwe Geological Survey. 18: 18–26.