A microfossil with suggested affinities to the Peronosporomycetes (Oomycota) from the Carboniferous (c. 330 Ma) of France

Carla J. Harper (1) , Michael Krings (1, 2) , Jean Galtier (3) , Thomas N. Taylor (1)

1 Department of Ecology and Evolutionary Biology, University of Kansas
2 Bayerische Staatssammlung für Paläontologie und Geologie und GeoBio-Center
3 UMR AMAP - Botanique et Modélisation de l'Architecture des Plantes et des Végétations

Combresomyces cornifer is a conspicuous spheroidal microfossil (<40 μm diam.) that occurs in Mississippian (~330 Ma) chert from France and is characterized by a prominent surface ornament of antler-like extensions positioned on hollow, conical or column-like wall papillations. The fossil has been interpreted as a peronosporomycete oogonium based on appressed paragynous antheridia. Here we report Annelaurea excornis nov. gen. et sp., a new fossil from the French Mississippian chert that resembles C. cornifer in overall morphology, but is distinctly thicker-walled and lacks the antler-like extensions. Moreover, size and shape of the papillations vary greatly within one specimen. This discovery suggests that by the Carboniferous the peronosporomycetes were already a morphologically diverse group

Keywords: AMPHIGYNOUS ANTHERIDIUM; COMBRESOMYCETACEAE; Neck; Oogonium Stalk; Oospore; Palaeobotany; Carboniferous

Domains: Biodiversity and Ecology; Vegetal Biology

Carla J. Harper, Michael Krings, Jean Galtier, Thomas N. Taylor. A microfossil with suggested affinities to the Peronosporomycetes (Oomycota) from the Carboniferous (c. 330 Ma) of France. Nova Hedwigia, 2016, 103 (3-4), pp.315-326. ⟨10.1127/nova_hedwigia/2016/0352⟩. ⟨hal-01392373⟩