| Titre : | A new genus for isolated bivalved sporangia with thickened margins from the Lower Devonian of the Welsh Borderland |
| Auteurs : | D. Edwards, Auteur ; L. Axe, Auteur ; E. Mendez, Auteur |
| Type de document : | Article |
| Dans : | Botanical Journal of the Linnean Society (137(3) 2001-11-01) |
| Article en page(s) : | 297-310 |
| Résumé : | A new taxon Sporathylacium salopense gen. et sp. nov. is based on small isolated coalified sporangia from the Lower Devonian (Lochkovian: micrornatus—newportensis spore zone) from the Welsh Borderland. The sporangia have two equal valves with multi-layered walls and thickened borders, and contain trilete crassitate, non-curvaturate isospores that are completely covered by a microgranular ornament with possible distal verrucate/murornate structures. They differ from zosterophyll sporangia in details of the presumed dehiscence zone extending around the entire free convex margin, particularly in the presence of a wedge of amorphous material between the valves, and in spore characters. Absence of any information relating to water-conducting cells prevents further assignment within the embryophytes. Spherical bodies associated with spores and a resilient sporangial lining are compared with similar structures in extant free-sporing plants and with Ubisch bodies. The mode of sporangial dehiscence involving anatomical modifications of the valve margins and the novel wedge of tissue which connects them remains speculative. |
| En ligne : | https://doi.org/10.1111/j.1095-8339.2001.tb01125.x |



