Hapalosiphonacean cyanobacteria (Nostocales) thrived amid emerging embryophytes in an early Devonian (407-million-year-old) landscape
Christine Strullu-Derrien,
Frédéric Fercoq,
Marc Gèze,
Paul Kenrick,
Florent Martos,
Marc-André Selosse,
Karim Benzerara,
Andrew H. Knoll
Affiliations
Christine Strullu-Derrien
Institut Systématique Évolution Biodiversité (UMR 7205), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, UA, 75005 Paris, France; Science Group, The Natural History Museum, Cromwell Road, London SW7 5BD, UK; Corresponding author
Frédéric Fercoq
Unité Molécules de Communication et Adaptation des Micro-organismes (MCAM, UMR7245), Muséum national d’Histoire naturelle, CNRS, 75005 Paris, France
Marc Gèze
Unité Molécules de Communication et Adaptation des Micro-organismes (MCAM, UMR7245), Muséum national d’Histoire naturelle, CNRS, 75005 Paris, France
Paul Kenrick
Science Group, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
Florent Martos
Institut Systématique Évolution Biodiversité (UMR 7205), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, UA, 75005 Paris, France
Marc-André Selosse
Institut Systématique Évolution Biodiversité (UMR 7205), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, UA, 75005 Paris, France; Institut Universitaire de France, 75005 Paris, France; Department of Plant Taxonomy and Nature Conservation, University of Gdańsk, 80-308 Gdańsk, Poland
Karim Benzerara
Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (UMR 7590), CNRS, Muséum national d'Histoire naturelle, Sorbonne Université, 75005 Paris, France
Andrew H. Knoll
Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
Summary: Cyanobacteria have a long evolutionary history, well documented in marine rocks. They are also abundant and diverse in terrestrial environments; however, although phylogenies suggest that the group colonized land early in its history, paleontological documentation of this remains limited. The Rhynie chert (407 Ma), our best preserved record of early terrestrial ecosystems, provides an opportunity to illuminate aspects of cyanobacterial diversity and ecology as plants began to radiate across the land surface. We used light microscopy and super-resolution confocal laser scanning microscopy to study a new population of Rhynie cyanobacteria; we also reinvestigated previously described specimens that resemble the new fossils. Our study demonstrates that all are part of a single fossil species belonging to the Hapalosiphonaceae (Nostocales). Along with other Rhynie microfossils, these remains show that the accommodation of morphologically complex cyanobacteria to terrestrial ecosystems transformed by embryophytes was well underway more than 400 million years ago.
