Cladoxylopsida Explained

The cladoxylopsids are an extinct group of plants related to ferns and sphenopsids.^[1]

They had a central trunk, from the top of which several lateral branches were attached. Fossils of these plants originate in the Middle Devonian to Early Carboniferous periods (around), mostly just as stems.

Cladoxylopsida contains two orders. The order Hyeniales is now included in Pseudosporochnales.^[2]

Intact fossils of the Middle Devonian cladoxylopsid Wattieza show it to have been a tree, the earliest identified in the fossil record as of 2007. In 2019, experts from Cardiff University, UK; Binghamton University and the New York State Museum discovered more fossils of Cladoxylopsida and Archaeopteris in a quarry in Cairo, New York.^[3]

A recent (2017) discovery in Xinjiang in China of early Late Devonian (Frasnian, ca. 374 Ma) silicified fossil cladoxylopsid tree trunks (diameter up to c.70 cm) with preserved cellular anatomy showed an internal arrangement with many xylem bundles in the outer part and none in the interior; each bundle was surrounded by its own cambium layer, by which the tree's trunk widened.^{[4] [5] [6]}

References

• 10.1038/nature05705. 17443185. Giant cladoxylopsid trees resolve the enigma of the Earth's earliest forest stumps at Gilboa. Nature. 446. 7138. 904–907. 2007. Stein. William E.. Mannolini. Frank. Hernick. Linda Vanaller. Landing. Ed. Berry. Christopher M.. 2575688. 2007Natur.446..904S.

External links

Links with images:

• UC Museum of Paleontology
• https://sites.google.com/site/paleoplant/classification/cladoxylopsid

Notes and References

1. Web site: Introduction to the Cladoxylopsida. live. https://web.archive.org/web/20211105020219/https://ucmp.berkeley.edu/plants/cladoxylopsida/cladoxylopsida.html. November 5, 2021. January 10, 2022. University of California Museum of Paleontology.
2. Thomas N. Taylor, Edith L. Taylor, Michael Krings: Paleobotany. The Biology and Evolution of Fossil Plants. Second Edition, Academic Press 2009,, p. 387-401, 1028
3. News: Foster . Laura . Dec 19, 2019 . World's oldest fossil trees uncovered in New York . . Dec 19, 2019.
4. 10.1073/pnas.1708241114. 29078324. 5692553. Unique growth strategy in the Earth's first trees revealed in silicified fossil trunks from China. Proceedings of the National Academy of Sciences. 114. 45. 12009–12014. 2017. Xu. Hong-He. Berry. Christopher M.. Stein. William E.. Wang. Yi. Tang. Peng. Fu. Qiang. free.
5. https://www.cardiff.ac.uk/news/view/981090-worlds-oldest-and-most-complex-trees (with image of trunk cross-section)
6. Web site: Prehistoric tree mystery baffles scientists. 2017-10-23.