Trimerophytopsida

Trimerophytopsida
Temporal range: Devonian
Fossil of Psilophyton dawsonii
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Class: †Trimerophytopsida
A.S.Foster & E.M.Gifford 1974
Order

†Trimerophytales

Synonyms[citation needed]
  • Trimerophyta (orth. var.)
  • Psilophyta (orth. var.)
  • Trimerophytophyta Bold 1973
  • Trimerophytophytina Banks 1975
  • Psilophytophyta Zimmermann 1930
  • Psilophytophytina Kryshtofovich 1945

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. Different authors have treated the group at different taxonomic ranks using the names Trimerophyta, Trimerophytophyta, Trimerophytina, Trimerophytophytina and Trimerophytales.