1978/03/01 by Sheila D. Brack‐Hanes · 3 citations
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · Earth and Planetary Sciences · #Lichen and fungal ecology #Protist diversity and phylogeny #Marine and coastal plant biology
paper · doi:10.1086/336979
openalex publication_date 1978/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/04/18
Lepidodendracean fructifications with well-preserved megagametophytes are described from Pennsylvanian petrifactions of eastern Kentucky. One cone is megasporangiate with one functional alate spore in each sporangium; the other cone is bisporangiate with spinose megaspores and papillate microspores. Both strobili have megaspores that contain prothallia with rhizoids and well-developed archegonia. Ontogenetic stages of megagametophytic development in these cones are comparable to stages that occur in extant heterosporous lycopods. This study provides further evidence of a close phylogenetic relationship between the lepidodendrids and the extant genus Isoetes.