Abstract Detail

Fossil plants at the intersection of evo-devo and phylogeny: celebrating the contributions of Gar W. Rothwell to biodiversity and evolution

Harper, Carla [1], Galtier, Jean [2], Rößler, Ronny [3], Taylor, Edith L. [4], Krings, Michael [5].

Spatial distribution of fungi in an enigmatic Triassic fern stem from central Europe.

The vast majority of Mesozoic ferns can be attributed to modern orders and families. A notable exception is Knorripteris/Adelophyton, an anatomically preserved Triassic fern stem that has enigmatic systematic affinities as it differs fundamentally from stem organizations seen in any other fossil or modern fern family. Documented evidence of fungi in Mesozoic ferns is exceedingly rare. In this contribution, we present a newly rediscovered specimen of Knorripteris/Adelophyton from the Franconian region of Germany that is colonized by several different morphotypes of fungal remains. The exquisite preservation of nearly all internal tissues throughout a ~10 cm long portion of the stem enables precise documentation of the spatial distribution of the fungi based on series of longitudinal and transverse sections. Two distinctive size classes of fungal hyphae, as well as various types of propagules are present: relatively small, tenuous hyphae (1–2.5 µm wide) primarily occur throughout the cortex, while large hyphae (3–7 µm wide) are most abundant in the cortical layers directly adjacent to the phloem. Wide hyphae sometimes also occur within tracheids. Spherical and pyriform propagules occur exclusively in phloem cells and in the cortex layers adjacent to the phloem. Hyphae attached to these propagules have not been found; however, the small, tenuous hyphae mentioned above correspond in diameter to the attachment point(s) visible in many of the propagules. Finally, moniliform hyphae, some with attached conidiophores, are the rarest morphotype and located exclusively in the periphery of the stele sensu lato. The precise affinities of the fungus (or fungi) cannot be determined, but some of the remains are reminiscent of certain present-day Ascomycota and possibly dark septate endophytes (DSE). No host responses associated with the fungi have been observed; however, preservation quality of the host strongly suggests that the fern was alive during fungal colonization.

1 - University Of Kansas, Ecology And Evolutionary Biology, 1200 Sunnyside Ave, Haworth Hall, Lawrence, KS, 66045, United States
2 - Botanique Et Bioinformatique De L’Architecture Des Plantes, TA40/PS2, Boulevard De La Lironde, F-34398, Montpellier, Cedex 5, France
3 - Museum für Naturkunde Chemnitz, Moritzstraße 20, Chemnitz, 09111, Germany
4 - University of Kansas, Ecology and Evolutionary Biology and Biodiversity Institute, 1200 Sunnyside Drive, Haworth Hall, Lawrence, Kansas, 66045, United States
5 - Bayerische Staatssammlung Für Paläontologie Und Ge, Richard-Wagner Strasse 10, Munich, D-80333, Germany

Keywords:
Triassic
fossil fungi
fern
Germany
Spatial analysis
Mesozoic.

Presentation Type: Colloquium Presentations
Session: C11a, Fossil plants at the intersection of evo-devo and phylogeny: celebrating the contributions of Gar W. Rothwell to biodiverstiy and evolution Part 1
Location: 110/Mayo Civic Center
Date: Wednesday, July 25th, 2018
Time: 10:15 AM
Number: C11a007
Abstract ID:510
Candidate for Awards:None