GSA Annual Meeting in Denver, Colorado, USA - 2016

Paper No. 118-5
Presentation Time: 2:30 PM

REASSESSMENT OF THE DEVONIAN PROBLEMATICUM PROTONYMPHA AS ANOTHER POST-EDIACARAN VENDOBIONT


RETALLACK, Gregory J., Department of Geological Sciences, University of Oregon, Eugene, OR 97403, gregr@uoregon.edu

Protonympha is an enigmatic fossil represented by two species from the Middle (P. transversa) and Late Devonian (P. salicifolia) of New York. Although interpreted in the past as a polychaete worm or starfish arm, Protonympha is not found with marine fossils, but with fossil plants of a community dominated by lycopsids. This community was a swamp woodland of Lepidosigillaria whitei, with ground cover of Haskinsia colophylla, fringing brackish to freshwater coastal lagoons of the Catskill Delta. Protonympha shares with Ediacaran Vendobionta a quilted body of unskeletonized biopolymer that is unusually resistant to burial compaction. In overall form, Protonympha is remarkably similar to the Ediacaran genus Spriggina and can be provisionally regarded as the geologically youngest representative of the Family Sprigginidae and Order Rangeomorpha. Protonympha has branching and tapering rhizines radiating from one end. These rhizines, thallus stratification, and internal chambers revealed by petrographic thin sections, suggest affinities with lichenized Fungi. As for Cambrian Swartpuntia, and Ordovician-Silurian Rutgersella, Protonympha may have been a post-Ediacaran vendobiont.