Mycological Progress

, Volume 8, Issue 1, pp 9–18

Acaulosporoid glomeromycotan spores with a germination shield from the 400-million-year-old Rhynie chert

  • Nora Dotzler
  • Christopher Walker
  • Michael Krings
  • Hagen Hass
  • Hans Kerp
  • Thomas N. Taylor
  • Reinhard Agerer
Original Article

DOI: 10.1007/s11557-008-0573-1

Cite this article as:
Dotzler, N., Walker, C., Krings, M. et al. Mycol Progress (2009) 8: 9. doi:10.1007/s11557-008-0573-1

Abstract

Scutellosporites devonicus from the Early Devonian Rhynie chert is the only fossil glomeromycotan spore taxon known to produce a germination shield. This paper describes a second type of glomeromycotan spore with a germination shield from the Rhynie chert. In contrast to S. devonicus, however, these spores are acaulosporoid and develop laterally in the neck of the sporiferous saccule. Germination shield morphology varies, from plate-like with single or double lobes to tongue-shaped structures usually with infolded margins that are distally fringed or palmate. Spore walls are complex and appear to be constructed of at least three wall groups, the outermost of which includes the remains of the saccule. The complement of features displayed by the fossils suggests a relationship with the extant genera Ambispora, Otospora, Acaulospora or Archaeospora, but which of these is the closest extant relative cannot be determined. The acaulosporoid spores from the Rhynie chert document that this spore type was in existence already ∼400 mya, and thus contribute to a more complete understanding of the evolutionary history of the Glomeromycota. This discovery pushes back the evolutionary origin of all main glomeromycotan groups, revealing that they had evolved before rooted land plants had emerged.

Keywords

Fossil fungiGlomeromycotaPragian-?earliest Emsian (Early Devonian)Spore-saccule complexSpore wall

Copyright information

© German Mycological Society and Springer 2008

Authors and Affiliations

  • Nora Dotzler
    • 1
    • 2
  • Christopher Walker
    • 3
  • Michael Krings
    • 1
    • 4
  • Hagen Hass
    • 5
  • Hans Kerp
    • 5
  • Thomas N. Taylor
    • 4
  • Reinhard Agerer
    • 2
  1. 1.Bayerische Staatssammlung für Paläontologie und Geologie und GeoBio-CenterLMULudwig-Maximilians-Universität MünchenMunichGermany
  2. 2.Department Biologie I und GeoBio-CenterLMU, Organismische Biologie: MykologieLudwig-Maximilians-Universität MünchenMunichGermany
  3. 3.Royal Botanic Garden EdinburghEdinburghUK
  4. 4.Department of Ecology and Evolutionary Biology, and Natural History Museum and Biodiversity Research CenterThe University of KansasLawrenceUSA
  5. 5.Forschungsstelle für Paläobotanik am Geologisch-Paläontologischen InstitutWestfälische Wilhelms-Universität MünsterMünsterGermany