A fungal community in plant tissue from the Lower Coal Measures (Langsettian, Lower Pennsylvanian) of Great Britain

Abstract

A diverse assemblage of microfungal remains occurs in periderm cells of a lycophyte from the Lower Coal Measures (Carboniferous) of Great Britain. Among the remains are several types of hyphae, including septate forms with catenulate swellings and small, narrow forms that are multi-branched. There are also several types of spherical structures that differ from one another in size, wall thickness, and ornamentation. The most common of these is interpreted as peronosporomycete oogonia based on specimens with attached antheridia. Other forms may also represent Peronosporomycetes, but might as well belong to the Zygomycota. Oval or tear drop-like structures that occur in clusters or chains are interpreted as conidia. Host reactions in the periderm cells are rare, with the exception of small callosities. Although it is not possible to conclusively identify the (precise) systematic affinities of the fungi, this discovery is significant because it demonstrates that one of the most common plant tissues in the Carboniferous (i.e. lycophyte periderm) provided a suitable habitat for several endophytic organisms at the same time. The overall excellent preservation of the host tissue, together with the evidence of host reactions, indicates that at least some of the endophytes were biotrophic.•

Fungi in a Psaronius root mantle from the Rotliegend (Asselian, Lower Permian/Cisuralian) of Thuringia, Germany

“…Carboniferous/Permian assemblages of fungi and fungus-like organisms comparable in diversity to that seen in the Manebach root mantle have previously been described in the periderm of arborescent lycophytes (Krings et al, 2007(Krings et al, , 2010a and in stems and pinna axes of the lyginopteridalean seed fern Lyginopteris oldhamia (Binney) H. Potonié (Strullu-Derrien et al, 2011;Krings et al, 2014). Together with the Manebach root mantle fungi, these discoveries strengthen the hypothesis that associations between fungi and plants were highly diverse and complex in the Carboniferous/early Permian coal swamp forests, likely because many coal swamp plants were long lived and complex in morphology and internal organization, and thus have provided multiple contact sites and ecologically distinct microhabitats for fungi (Krings et al, 2010a(Krings et al, , 2012. We anticipate that, as additional specimens of Psaronius root mantles from Manebach and elsewhere are systematically screened for fungi, it will be possible to piece together the life histories of some of the fungi associated with these remarkable tree ferns and more accurately assess their systematic affinities.…”

The epiphytic plants in the fossil record and its example from in situ tuff from Pennsylvanian of Radnice Basin (Czech Republic).

“…Fungal epiphytes of Pennsylvanian age growing on Cordaites leafs or tree fern pinnules were described by Krings et al (2010aKrings et al ( , 2010bKrings et al ( , 2011. Epiphytic fungi are also described from Early Cretaceous cycad leaves (Shao-lin & Wu 1986).…”

“…Consequently, this sampling bias can influence the general view of the evolution of all plants and nature including the evolution of epipfytes. During palaeobotanical history many vascular (Mamay 1952, Rothwell 1991, Rößler 2000 and microphytic plants (Shao-lin & Wu 1986;Krings et al 2010aKrings et al , 2010bKrings et al , 2011 have been interpreted as epiphytes. However, most of these attributions are based only on indirect evidence.…”

“…Extinct epiphytes are known from several groups such as fungi (Krings et al 2010a(Krings et al , 2010b(Krings et al , 2011, lichens or mosses, as well as vascular plants such as ferns (Mamay 1952, Rothwell 1991, Schneider & Kenrick 2001, Goméz 1982, magnoliophytes (Benzing 1990), cycads and rarely from gnetophytes (Benzing 1990). Late Paleozoic epiphytes are known also among some extinct pteridosperm groups (Krings et al 2003, DiMichele et al 2006.…”

Distribution of fungi in a Triassic fern stem

“…Moreover, series of peels or thin sections of single, exquisitely preserved plant specimens are needed in order to accurately document fungal distribution, but these are rarely available, especially for larger axes or trunks. As a result, information on spatial arrangement of fungi that is provided in descriptions of fossil plant-fungus associations has been obtained usually from small areas of the host plant or from single sections (e.g., Krings et al 2007Krings et al , 2010. However, the spatial distribution of fungal remains within a plant represents a proxy indicator for fungal colonisation pathways and infection strategies, and thus may provide valuable insights into the nature of the relationship between a fossil fungus and its host plant.…”