Reassessment of the Silurian problematicum Rutgersella as another post-Ediacaran vendobiont

Abstract

Retallack, G.J., 1.7.2015. Reassessment of the Silurian problematicum Rutgersella as another post-Ediacaran vendobiont. Alcheringa 39, 573–588. ISSN 0311-5518

Rutgersella is a problematic fossil from the early Silurian (Llandovery) Shawangunk Formation of New Jersey, at first interpreted as a jellyfish comparable with Ediacaran fossils, such as Dickinsonia. Three proposed species of Rutgersella from the same locality are here regarded as growth or reproductive variants of a single species, R. truexi. Sedimentary structures, associated trace fossils and petrographic examination now show that they were sessile organisms of intertidal mudflats. These fossils have been dismissed as pyrite suns, but thin-sections show that they were weakly pyritized, organic structures, with a quilted hollow internal structure, similar to Seilacher’s constructional and taxonomic concept of Vendobionta. As for Cambrian Swartpuntia, and Devonian Protonympha, Rutgersella may be a post-Ediacaran vendobiont. The biological affinities of Rutgersella are problematic, but are compared with coenocytic green algae, cellular slime moulds, puffball-like fungal fruiting bodies and foliose lichens.

Gregory J. Retallack [[email protected]], Department of Geological Sciences, University of Oregon, Eugene, OR 97403-1272, USA.

Key words:

• Rutgersella
• Silurian
• Pennsylvania
• Problematicum
• Vendobiont

Acknowledgements

Nora Noffke, Stefan Bengtson, James Hagadorn and Erle Kauffman offered useful discussion. Edward Davis aided with photography and Kurt Langworthy helped with scanning electron microscopy. Lauren Neitzke-Adamo, of Rutgers Geology Museum, helped with information about type specimens of Rutgersella, and Robert William Selden graciously provided photographs of them.