Article · Wikipedia archive · Last revised Jun 17, 2026

Armoricaphyton

Armoricaphyton is an extinct monospecific genus of vascular land plants described from Early Devonian outcrops of the Chalonnes Formation in western France. The plant consists of small, leafless, longitudinally-ribbed axes that branch pseudomonopodially. Pairs of fusiform-shaped, twisted sporangia preserved as adpressions were found in association with the axes and may belong to this species. Permineralized specimens reveal the oldest documented wood or secondary xylem of any known fossil plant. The water-conducting tissues or tracheids consisted of extinct P-type cell walls. This type of cell wall consisted of scalariform bordered pits and perforated sheets that covered the openings (apertures) of the pits. A. chateaupannense is anatomically similar in some respects to other members of the Euphyllophytina such as Psilophyton and Franhueberia. Franhueberia gerriennei is also one of the earliest land plants described from the Early Devonian that was known to have wood. Given the differences between Armoricaphyton and these other genera and a lack of a complete understanding of the whole plant, Armoricaphyton is currently classified as Euphyllophytina incertae sedis.

Last revised
Jun 17, 2026
Read time
≈ 1 min
Length
292 w
Citations
6
Source
Wikipedia ↗
Armoricaphyton
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Embryophytes
Clade: Tracheophytes
Clade: Euphyllophytes
Family: incertae sedis
Genus: †Armoricaphyton

Armoricaphyton is an extinct monospecific genus of vascular land plants described from Early Devonian (late Pragian-earliest Emsian) outcrops of the Chalonnes Formation in western France.1 The plant consists of small, leafless, longitudinally-ribbed axes that branch pseudomonopodially. Pairs of fusiform-shaped, twisted sporangia preserved as adpressions were found in association with the axes and may belong to this species.1 Permineralized specimens reveal the oldest documented wood or secondary xylem of any known fossil plant. The water-conducting tissues or tracheids consisted of extinct P-type cell walls. This type of cell wall consisted of scalariform bordered pits and perforated sheets that covered the openings (apertures) of the pits.1 A. chateaupannense is anatomically similar in some respects to other members of the Euphyllophytina such as Psilophyton and Franhueberia.1 Franhueberia gerriennei is also one of the earliest land plants described from the Early Devonian (late Emsian) that was known to have wood.2 Given the differences between Armoricaphyton and these other genera and a lack of a complete understanding of the whole plant, Armoricaphyton is currently classified as Euphyllophytina incertae sedis.1

See also

See also

References

References

  1. Strullu-Derrien, Christine; Kenrick, Paul; Tafforeau, Paul; Cochard, Hervé; Bonnemain, Jean-Louis; Le Hérissé, Alain; Lardeux, Hubert; Badel, Eric (2014). "The earliest wood and its hydraulic properties documented in c. 407-million-year-old fossils using synchrotron microtomography". Botanical Journal of the Linnean Society. 175 (3): 423–437. doi:10.1111/boj.12175.
  2. Hoffman, Laurel A.; Tomescu, Alexandru M.F. (2013). "An early origin of secondary growth: Franhueberia gerriennei gen. et sp. nov. from the Lower Devonian of Gaspé (Quebec, Canada)" (PDF). American Journal of Botany. 100 (4): 754–763. doi:10.3732/ajb.1300024. PMID 23535772. S2CID 33812157. Archived from the original (PDF) on 2019-02-20.