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]

Armoricaphyton
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Euphyllophytes
Family:	incertae sedis
Genus:	†Armoricaphyton