The macrofossil Lydonia jiggamintia gen. et sp. nov. from the Ediacaran of Newfoundland (Canada): From pseudofossil to metazoan-grade organism

The Ediacaran rocks from Discovery UNESCO Global Geopark on the Bonavista Peninsula, Newfoundland (CA), contain a rich fossil record, with remarkable preservation and an unusually great abundance of diverse Ediacaran organisms.This study focuses on the large (<40 cm), enigmatic taxon, previously described as "Blackbrookia", that is particularly common on the Johnson Discovery Surface along with the super-abundant rangeomorph Fractofusus andersoni (<30.000specimens).Unlike the pseudofossil Blackbrookia, the form under consideration is interpreted as a body fossil and reclassified herein (Lydonia jiggamintia gen.et sp.nov.).Lydonia is characterized by infilled pores on its upper surface, which we consider to be related to the presence of an aquiferous system.We compare this morphology to various extant and extinct macro-organisms and note that Lydonia might be analogous to modern encrusting Porifera in its body plan.Statistical analyses of Lydonia populations allow us to reconstruct the morphospace occupied by the species, as well as to consider aspects of ontogeny and population structure.We recognize a metazoan-grade morphology and mode of life, even though the phylogenetical affinity remains ambiguous.If accepted as a metazoan, Lydonia would constitute further evidence for animal life in the Ediacaran, with important implications for our understanding of the record of early animals and evidence for lengthening the Ediacaran food chain.