Abstract Detail

Paleobotany

Harper, Carla J [1], Krings, Michael [1], Taylor, Edith L [2].

The Windyfield chert (Lower Devonian, Scotland): Exceptional preservation of chytrid-like fungi and fungal interactions with charophytes.

The Windyfield chert is a chert deposit in close proximity and broadly coeval to the world famous Lower Devonian Rhynie chert site. Recent screening of Windyfield chert blocks has yielded multiple specimens of distinctive microorganisms that have not been recorded from the Rhynie chert. Several different types of parasitic interactions between charophytes and chytrid-like microfungi were documented some 25 years ago from the Rhynie chert. Those chytrid-like organisms (formally described as Milleromyces, Lyonomyces, and Krispiromyces) were characterized by epibiotic or endobiotic zoosporangia and rhizomycelia extending into the host; some were the causative agents of hypertrophy in the form of drastically inflated algal cells. Newly discovered in-situ stands of charophytes from the Windyfield chert also contain representatives of the fungal taxa described in the original study, as well as several new forms, including one that is characterized by particularly thick walled, drop-shaped zoosporangia and multi-branched, tenuous rhizomycelia. Another form possesses short-stalked, lacrimoid zoosporangia with a single distal discharge opening. Other evidence of chytrid-like organisms in the Windyfield chert includes zoosporangia entirely surrounded by what appears to be a prominent mucilage sheath strikingly similar to that seen in certain extant species of the chytrid Rhizophydium. The lumen of the zoosporangium is filled with numerous spherules that contain dark central inclusions; in rare cases, zoosporangia are attached to thick rhizomycelia. The Windyfield chert fossils demonstrate that (1) charophyte algae in Early Devonian freshwater ecosystems served as hosts to a much wider range of microscopic fungi and probably to other groups of microorganisms and (2) the diversity of chytrid-like organisms in these early non-marine ecosystems was greater than previously thought.

1 - Ludwig-Maximilians-Universität, Department für Geo- und Umweltwissenschaften, Paläontologie und Geobiologie, Richard-Wagner-Straße 10, Munich, 80333, Germany
2 - University Of Kansas, Department Of Ecology And Evolutionary Biology, 1200 Sunnyside Avenue, Haworth Hall, Lawrence, KS, 66045-7600, USA

Keywords:
fossil fungi
green algae
interactions
Chytridiomycota
parasitism
Rhynie chert.

Presentation Type: Oral Paper
Session: 16, Cookson/Moseley and Paleozoic paleobotany
Location: Sundance 4/Omni Hotel
Date: Monday, June 26th, 2017
Time: 4:45 PM
Number: 16005
Abstract ID:139
Candidate for Awards:None