title: Combresomyces cornifer gen. sp. nov., an endophytic peronosporomycete in Lepidodendron from the Carboniferous of central France.
abstract: Structurally preserved periderm of the lycophyte Lepidodendron rhodumnense from the Visean (Mississippian) of central France contains a peronosporomycete (Combresomyces cornifer gen. sp. nov.) that occurs in the form of pyriform to subglobose terminal oogonia. On the surface is a conspicuous ornamentation, which may have formed through condensation of a mucilaginous extra-oogonial wall secretion. Some oogonia contain thin-walled spherules, which may represent (walled) oospheres or spores of an endoparasitic fungus (?chytrid), whereas single, large spheres in the interior are interpreted as oospores. Antheridia adpressed to several of the specimens are clavate and paragynous. This discovery sheds light on the morphology and biology of peronosporomycetes in a terrestrial ecosystem some 330My ago. Although the organism occurs exclusively in the periderm of L. rhodumnense, it is not known whether it represents a symptomless endophyte, pathogen, or saprotroph.
authors.affiliation: Bayerische Staatssammlung für Paläontologie und Geologie und GeoBio-Center(LMU), Richard-Wagner-Strasse 10, 80333 Munich, Germany.
authors.forename: Nora
authors.initials: N
authors.lastname: Dotzler
authors.forename: Michael
authors.initials: M
authors.lastname: Krings
authors.forename: Reinhard
authors.initials: R
authors.lastname: Agerer
authors.forename: Jean
authors.initials: J
authors.lastname: Galtier
authors.forename: Thomas N
authors.initials: TN
authors.lastname: Taylor
mesh_terms: D044002:Bryophyta / Q000382:microbiology* / Q000648:ultrastructure; D005580:Fossils; D005602:France; D009868:Oomycetes / Q000145:classification* / Q000235:genetics / Q000648:ultrastructure; D010935:Plant Diseases / Q000382:microbiology; D013045:Species Specificity; D013172:Spores, Fungal / Q000648:ultrastructure