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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 (about 420 to 360 million years ago ). Specimens have been found in northern Maine , USA; Gaspé Bay , Quebec and New Brunswick , Canada; the Czech Republic ; and Yunnan , China.
After Gwynne-Vaughan's death in 1915 [4] he studied preserved plant remnants in Aberdeen, making great insights into the nature of Psilophyton, which until then had been neglected. [3] In 1900 he was awarded a Doctor of Science degree by the University of Glasgow, and when the Barker chair of cryptogamic botany was created at the University of ...
Psilotum is a genus of fern-like vascular plants.It is one of two genera in the family Psilotaceae commonly known as whisk ferns, the other being Tmesipteris.Plants in these two genera were once thought to be descended from the earliest surviving vascular plants, but more recent phylogenies place them as basal ferns, as a sister group to Ophioglossales.
Trimerophytopsida (or Trimeropsida) is a class of early vascular plants from the Devonian, informally called trimerophytes.It contains genera such as Psilophyton.This group is probably paraphyletic, and is believed to be the ancestral group from which both the ferns and seed plants evolved.
Three genera were initially included, Rhynia, Horneophyton and Psilophyton. All lacked leaves and true roots, consisting only of branched stems; however they were considered to contain vascular tissue. [1] Additional fossil genera were added later. As described by Sporne in 1966, Psilophytopsida consisted of four families: [5] Rhyniaceae
Trimerophytes comprised plants with large clusters of downwards curving terminal sporangia that split along their length to release their spores and had centrarch xylem strands (e.g., Psilophyton). [19] Research by Kenrick and Crane that established the polysporangiophytes concluded that none of Banks' three groups were monophyletic.
At first most of the fossilized early land plants other than bryophytes were placed in the class Psilophyta, established in 1917 by Kidston and Lang. [9] As additional fossils were discovered and described, it became apparent that the Psilophyta were not a homogeneous group of plants, and in 1975 Banks developed his earlier proposal to split it into three groups, which he put at the rank of ...
The identification of plant fossils in Cambrian strata is an uncertain area in the evolutionary history of plants because of the small and soft-bodied nature of these plants. It is also difficult in a fossil of this age to distinguish among various similar appearing groups with simple branching patterns, and not all of these groups are plants.