scholarly journals Rhizophydites matryoshkae gen. et sp. nov. (Fossil Chytridiomycota) on Spores of the Early Land Plant Horneophyton lignieri from the Lower Devonian Rhynie Chert

2021 ◽  
Vol 182 (2) ◽  
pp. 109-122 ◽  
Author(s):  
Michael Krings ◽  
Sharyn M. Serbet ◽  
Carla J. Harper
Keyword(s):  
Lower Devonian ◽  
Land Plant ◽  
Early Land Plant ◽  
Rhynie Chert ◽  
Early Land

scholarly journals Archaeosporites rhyniensis gen. et sp. nov. (Glomeromycota, Archaeosporaceae) from the Lower Devonian Rhynie chert: a fungal lineage morphologically unchanged for more than 400 million years

2020 ◽  
Vol 126 (5) ◽  
pp. 915-928 ◽  
Author(s):  
Carla J Harper ◽  
Christopher Walker ◽  
Andrew B Schwendemann ◽  
Hans Kerp ◽  
Michael Krings
Keyword(s):  
Lower Devonian ◽  
Arbuscular Mycorrhizas ◽  
Land Plant ◽  
Thin Sections ◽  
Early Devonian ◽  
Fungal Lineage ◽  
Transmitted Light Microscopy ◽  
Rhynie Chert ◽  
History Of ◽  
Early Land

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.

scholarly journals Ultrastructure of laevigate hilate spores in sporangia and spore masses from the Upper Silurian and Lower Devonian of the Welsh Borderland

1998 ◽  
Vol 353 (1378) ◽  
pp. 1983-2004 ◽  
Author(s):  
C. H. Wellman ◽  
D. Edwards ◽  
L. Axe
Keyword(s):  
Electron Microscope ◽  
Lower Devonian ◽  
Spore Wall ◽  
Land Plant ◽  
White Line ◽  
Early Land Plant ◽  
Wall Ultrastructure ◽  
Spore Mass ◽  
Upper Silurian ◽  
Early Land

Spore masses and isolated sporangia, containing laevigate hilate cryptospores attributable to the dispersed taxon Laevolancis divellomedia sensu lato , have been recovered on bulk maceration of Upper Silurian (Pridoli) and Lower Devonian (Lochkovian) deposits from the Welsh Borderland. Detailed morphological, anatomical and ultrastructural analysis, using light microscope, scanning electron microscope and transmission electron microscope techniques, reveals subtle differences between the specimens and they can be grouped into five distinct types. The different groups are distinguished principally by using sporangia–spore mass characteristics, presence or absence of extra–exosporal material and nature of spore–wall ultrastructure. Of the groups, one has a uniformly homogeneous exospore and the other four groups have a bilayered exospore. In the former the spores lack extra–exosporal material and occur in a discoidal sporangium. Of the bilayered groups, two have exospores of homogeneous composition but with the two layers differing in electron density. They occur in discoidal sporangia and spore masses and are distinguished on the presence or absence of extra–exosporal material and differences in the widths of the two layers. Finally, two bilayered groups possess a lamellate inner layer, but vary in presumed sporangial shape. Elongate sporangia have spores with concentric continuous lamellae, lacking further ultrastructure. In contrast, spores from a discoidal spore mass have white–line–centred, presumably tripartite, lamellae which are laterally discontinuous, overlapping and irregularly spaced. These findings, which suggest that morphologically similar spores were produced by a number of plant taxa, have important implications regarding the assessment of early land–plant diversity. The affinities of hilate cryptospore–producing plants are unknown and problematic, particularly as no extant non–angiosperm plants produce dyads, other than through meiotic irregularity, and spore–sporangial characters have no exact counterpart in coeval plants. Studies of specimens with in situ hilate cryptospores suggest that they derive from rhyniophytoids, i.e. plants that resemble the simplest of vascular plants but lack evidence of vascular tissue, although hilate cryptospore–containing examples show no axial branching. It might be argued, based on evidence from spore wall ultrastructure, that some of the plants have more in common with lycopsids and filicopsids than bryophytes, a surprising finding bearing in mind the stratigraphic distribution of hilate cryptospores–dyads and inferences that the producers were bryophyte–like. Detailed studies of wall structure in the hilate cryptospores permit consideration of spore wall development. It is suggested that extra–exosporal material derives from a tapetum and is thus produced by the diploid sporophyte. The white–line–centred lamellae in a single specimen provide the earliest evidence for the presence of such structures in early land plant spores and provide further evidence that sporopollenin deposition on such structures is the most primitive mode of sporopollenin deposition among land plants.

scholarly journals The hornwort genome and early land plant evolution

Nature Plants ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 107-118 ◽  
Author(s):  
Jian Zhang ◽  
Xin-Xing Fu ◽  
Rui-Qi Li ◽  
Xiang Zhao ◽  
Yang Liu ◽  
...  
Keyword(s):  
Land Plant ◽  
Plant Evolution ◽  
Early Land Plant ◽  
Land Plant Evolution ◽  
Early Land

Diversification of fts Z During Early Land Plant Evolution

2004 ◽  
Vol 58 (2) ◽  
pp. 154-162 ◽  
Author(s):  
Stefan A. Rensing ◽  
Justine Kiessling ◽  
Ralf Reski ◽  
Eva L. Decker
Keyword(s):  
Land Plant ◽  
Plant Evolution ◽  
Early Land Plant ◽  
Land Plant Evolution ◽  
Early Land

Contributions to early land plant research (XVI IBC)

2001 ◽  
Vol 116 (1-2) ◽  
pp. vii
Author(s):  
Philippe Gerrienne ◽  
Christopher Berry
Keyword(s):  
Land Plant ◽  
Early Land Plant ◽  
Plant Research ◽  
Early Land

scholarly journals Complete plastome sequences of Equisetum arvense and Isoetes flaccida: implications for phylogeny and plastid genome evolution of early land plant lineages

2010 ◽  
Vol 10 (1) ◽  
pp. 321 ◽  
Author(s):  
Kenneth G Karol ◽  
Kathiravetpillai Arumuganathan ◽  
Jeffrey L Boore ◽  
Aaron M Duffy ◽  
Karin DE Everett ◽  
...  
Keyword(s):  
Genome Evolution ◽  
Plastid Genome ◽  
Land Plant ◽  
Equisetum Arvense ◽  
Early Land Plant ◽  
Plastid Genome Evolution ◽  
Early Land

An exceptional specimen of the early land plant Cooksonia paranensis, and a hypothesis on the life cycle of the earliest eutracheophytes

2006 ◽  
Vol 142 (3-4) ◽  
pp. 123-130 ◽  
Author(s):  
Philippe Gerrienne ◽  
David L. Dilcher ◽  
Sérgio Bergamaschi ◽  
Ingrid Milagres ◽  
Egberto Pereira ◽  
...  
Keyword(s):  
Life Cycle ◽  
Land Plant ◽  
Early Land Plant ◽  
Early Land

scholarly journals An Alternative Mode of Early Land Plant Colonization by Putative Endomycorrhizal Fungi

2007 ◽  
Vol 2 (2) ◽  
pp. 125-126 ◽  
Author(s):  
Michael Krings ◽  
Thomas N. Taylor ◽  
Hagen Hass ◽  
Hans Kerp ◽  
Nora Dotzler ◽  
...  
Keyword(s):  
Land Plant ◽  
Plant Colonization ◽  
Alternative Mode ◽  
Early Land Plant ◽  
Early Land
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