The cladoxylopsids are an extinct group of plants related to ferns and

sphenopsid Equisetidae is one of the four subclasses of Polypodiopsida (ferns), a group of vascular plants with a fossil record going back to the Devonian. They are commonly known as horsetails. They typically grow in wet areas, with whorls of needle-lik ...

s. They had a central trunk, from the top of which several lateral branches were attached. Fossils of these plants originate in the

Middle Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, wher ...

Early Carboniferous Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Ear ...

periods (around ), mostly just as stems. Cladoxylopsida contains two orders. The order Hyeniales is now included in Pseudosporochnales. Intact fossils of the

cladoxylopsid ''

Wattieza ''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 (publicly revealed in 2007) discovery in Schoharie County, New York ...

'' show it to have been a tree, the earliest identified in the fossil record as of 2007. In 2019, experts from

Cardiff University , latin_name = , image_name = Shield of the University of Cardiff.svg , image_size = 150px , caption = Coat of arms of Cardiff University , motto = cy, Gwirionedd, Undod a Chytgord , mottoeng = Truth, Unity and Concord , established = ...

, UK;

Binghamton University The State University of New York at Binghamton (Binghamton University or SUNY Binghamton) is a public research university with campuses in Binghamton, Vestal, and Johnson City, New York. It is one of the four university centers in the State ...

and the

New York State Museum The New York State Museum is a research-backed institution in Albany, New York, United States. It is located on Madison Avenue, attached to the south side of the Empire State Plaza, facing onto the plaza and towards the New York State Capitol ...

discovered more fossils of Cladoxylopsida and

Archaeopteris ''Archaeopteris'' is an extinct genus of progymnosperm tree with fern-like leaves. A useful index fossil, this tree is found in strata dating from the Upper Devonian to Lower Carboniferous (), the oldest fossils being 385 million years old, and ...

in a quarry in

Cairo, New York Cairo is a town in Greene County, New York, United States. The population was 6,644 at the 2020 census. The town is in the southern part of the county, partly in the Catskill Park. The town contains a hamlet, also named Cairo. History The fi ...

. A recent (2017) discovery in Xinjiang in China of early Late Devonian (

Frasnian The Frasnian is one of two faunal stages in the Late Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Givetian Stage and followed by the Famennian Stage. Major reef-building was under way during th ...

, 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.

References

External links

Links with images:
UC Museum of Paleontology
*https://sites.google.com/site/paleoplant/classification/cladoxylopsid Devonian plants Middle Devonian first appearances Mississippian extinctions Plant classes {{carboniferous-plant-stub