Archaeosporites rhyniensis gen. et sp. nov. (Glomeromycota, Archaeosporaceae), from the Lower Devonian Rhynie chert a fungal lineage morphologically unchanged from more than 400 million years
Citation:
Harper, C.J., Walker, C., Schwendemann, A.B., Kerp, H., Krings, M., Archaeosporites rhyniensis gen. et sp. nov. (Glomeromycota, Archaeosporaceae), from the Lower Devonian Rhynie chert a fungal lineage morphologically unchanged from more than 400 million years, Annals of Botany, 2020, 126, 5, 915 - 928Download Item:
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Abstract:
Background and Aims: Structurally preserved arbuscular mycorrhizas from the Lower Devonian Rhynie chert represent core fossil evidence of the evolutionary history of mycorrhizal systems. Moreover, Rhynie chert fossils of glomeromycotan propagules suggest that this lineage of arbuscular fungi was morphologically diverse by the Early Devonian; however, only a small fraction of this diversity has been formally described and critically evaluated.
Methods: Thin sections, previously prepared by grinding wafers of chert from the Rhynie beds, were studied by transmitted light microscopy. Fossils corresponding to the description of Archaeospora spp. occurred in 29 slides, and were measured, photographed and compared with modern-day species in that genus.
Key Results: Sessile propagules <85 µm in diameter, some still attached to a sporiferous saccule, were found in early land plant axes and the chert matrix; they developed, in a similar manner to extant Archaeospora, laterally or centrally within the saccule neck. Microscopic examination and comparison with extant fungi showed that, morphologically, the fossils share the characters used to circumscribe the genus Archaeospora (Glomeromycota; Archaeosporales; Archaeosporaceae).
Conclusions: The fossils can be assigned with confidence to the extant family Archaeosporaceae, but because molecular analysis is necessary to place organisms in these taxa to present-day genera and species, they are placed in a newly proposed fossil taxon, Archaeosporites rhyniensis.
Author's Homepage:
http://people.tcd.ie/charperDescription:
PUBLISHED
Author: Harper, Carla
Type of material:
Journal ArticleCollections:
Series/Report no:
Annals of Botany;126;
5;
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Full text availableKeywords:
Acaulosporoid propagule, Spore wall, Acaulospores, Archaeosporites rhyniensis, Archaeospora spp, Archaeosporaceae, Glomeromycota, Glomeromycotan Arbuscular Fungi (GAF), Arbuscular mycorrhizal fungi (AMF), Early Devonian, Rhynie chert, Sporiferous sacculeSubject (TCD):
Smart & Sustainable Planet , DEVONIAN , FOSSIL , FUNGI , Fossil Fungi , Fossils , MICROFUNGI , MYCORRHIZAL , MYCORRHIZAL FUNGI , Rhynie chert , VESICULAR-ARBUSCULAR MYCORRHIZASDOI:
http://dx.doi.org/10.1093/aob/mcaa113Licences: