Deciphering interfungal relationships in the 410-million-yr-old Rhynie chert: Sporocarp formation in glomeromycotan spores

Abstract

Fungi today enter into relationships with other fungi in many ways. Although this was likely also the case in the geologic past, detailed descriptions of interfungal associations and interactions based on fossils remain scarce. Sporocarps bounded by a peridium-like envelope occur singly within the lumen of large glomeromycotan spores (Palaeomyces gordonii var. major) from the Lower Devonian Rhynie chert. The envelope consists of multi-branched, interlacing hyphae. At the tips of hyphae, extending from the envelope into the lumen are produced spheroidal to urn-shaped spores. Similar sporocarps are found in several present day species in the Glomeraceae. Clusters of spores, superficially resembling sporocarps, may also

Fungi and fungal interactions in the Rhynie chert: a review of the evidence, with the description ofPerexiflasca taylorianagen. et sp. nov.†

“…The overall morphology of T. annulifer resembles the extant genera Macrochytrium (Chytridiomycota) and Blastocladiella (Blastocladiomycota). However, the rhizoids are septate or pseudoseptate, a feature not known in extant [86][87][88], hyphae enveloping and subsequently penetrating glomeromycotinan vesicles [89] and small fungal propagules developing in glomeromycotinan vesicles (figure 2j ) [90]. Moreover, several examples of monocentric and polycentric chytrid-like organisms have been described as colonizers of fungal hyphae and spores (figure 1a -e).…”

“…(ii) Fungi -fungi Abundant evidence of interfungal associations have been reported from the Rhynie chert, including mycelia and reproductive structures inside large fungal spores (figure 2g) [86][87][88], hyphae enveloping and subsequently penetrating glomeromycotinan vesicles [89] and small fungal propagules developing in glomeromycotinan vesicles (figure 2j ) [90]. Moreover, several examples of monocentric and polycentric chytrid-like organisms have been described as colonizers of fungal hyphae and spores (figure 1a -e).…”

Rhizophydites matryoshkaegen. et sp. nov. (Fossil Chytridiomycota) on Spores of the Early Land PlantHorneophyton lignierifrom the Lower Devonian Rhynie Chert

“…4A-4D 1984); however, there is also evidence to suggest that some could be glomoid spores (e.g., fig. 4E; see Krings et al 2015;Harper et al 2017). Other documented examples of fungi associated with spores of A. majus are several different types of epibiotic putative chytrid zoosporangia, some with discharge pores or papillae and others containing large numbers of spherules interpreted as encysted zoospores (Taylor et al 1992b(Taylor et al : figs.…”

The Evolution and Fossil Record of Parasitism

“…Rhynie chert evidence of interfungal associations ranges from fungal mycelia and reproductive units in the lumen of other fungal reproductive units (Kidston and Lang 1921;Krings et al 2009aKrings et al , 2010aKrings et al , 2015Krings et al , 2016, to fungal hyphae enveloping and subsequently penetrating fungal vesicles (Krings and Taylor 2014b), to fungal reproductive units developing in glomeromycotan vesicles (Fig. 3.4a) (Harper et al 2017b).…”