Journal Article

Anatomically preserved Silurian ‘nematophytes’ from the Welsh Borderland (UK)

Dianne Edwards, Rosmarie Honegger, Lindsey Axe and Jennifer L Morris

in Botanical Journal of the Linnean Society

Published on behalf of The Linnean Society of London

Volume 187, issue 2, pages 272-291
Published in print May 2018 | ISSN: 0024-4074
Published online May 2018 | e-ISSN: 1095-8339 | DOI: https://dx.doi.org/10.1093/botlinnean/boy022
Anatomically preserved Silurian ‘nematophytes’ from the Welsh Borderland (UK)

More Like This

Show all results sharing these subjects:

  • Evolutionary Biology
  • Natural History
  • Plant Sciences and Forestry
  • Plant Evolution

GO

Show Summary Details

Preview

Abstract

Stratified charcoalified fragments of thalloid organisms with tripartite tissue construction have been isolated from the basal member of the Upper Silurian (upper Ludlow) Downton Castle Sandstone Formation, exposed near Ludlow, Shropshire (England) and are considered to have had fungal affinity. They are divided into two major groups. The more novel of these is characterized by a superficial cortex separated from a basal layer of interweaving hyphae by an intermediate zone of compressed indeterminate tissue and members are placed in a new taxon, Tristratothallus ludfordensis. In the second, the intermediate zone comprises hyphae arranged at right angles to the cortex (termed palisade). Some members resemble the tissue construction of Nematothallus described from the Lower Devonian (Lochkovian) of the Welsh Borderland and considered to belong to fungi, some of which were lichenized. A further type, which shows remains of polysporic asci, is thought to represent a fragment of an apothecium (a disc-shaped ascoma of an ascomycete) of a pezizomycete and is the earliest such record. Yet others are characterized by a perforate cortex with occasional protruding hyphae, tissue construction of which was also recorded in the Lower Devonian of the Welsh Borderland and considered to display fungal characteristics. Coalified ‘black patches’ are common on bedding surfaces throughout the latest Silurian and Early Devonian and frequently are associated with basal embryophytes and tracheophytes. Those reported here are the oldest known with three-dimensional organization, studied via scanning electron microscopy (SEM) and attributed to fungi, and include some ascomycetes. Similar encrustations occur in even earlier rocks and may have been important constituents of the cryptogamic ground cover, which is postulated to have preceded higher plant life on land.

Keywords: ascomycetes; Cosmochlaina; fungi; Nematothallus; Pezizomycetes

Journal Article.  7073 words.  Illustrated.

Subjects: Evolutionary Biology ; Natural History ; Plant Sciences and Forestry ; Plant Evolution

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content. subscribe or purchase to access all content.