Ediacaran biota on Bonavista Peninsula, Newfoundland, Canada

Abstract

Newly found fossils in the Conception and St. John's groups of the Bonavista Peninsula considerably extend the known geographic distribution of the Ediacaran fossils in Newfoundland. They occur in deepwater sediments and are preserved as epireliefs, forming census populations underneath volcanic ash layers throughout a more than 1 km thick turbiditic sequence. the exposed fossiliferous units comprise the Mistaken Point, Trepassey, Fermeuse, and Renews Head formations. the remains are tectonically deformed, with long axes of elliptical discs aligned parallel to cleavage strike; shortening of originally circular bedding surface features is on the order of 30-50% (averaging ~35%).The assemblage includesAspidella, Blackbrookia, Bradgatia, Charnia, Charniodiscus, Fractofusus, Hiemalora, andIvesheadia.These occur throughout the succession, withAspidellabeing the most common genus, followed byCharniaandCharniodiscus.Four new taxa are described, with candelabra-like fossils with aHiemalora-like base referred toPrimocandelabrum hiemaloranumn. gen. and sp., bush-like fossils toParviscopa bonavistensisn. gen. and sp., ladder-like fossils toHadryniscala avalonican. gen. and sp., and string-like fossils with basal disc toHadrynichorde catalinensisn. gen. and sp. the remains also include dubiofossils. The stratigraphic ranges of some taxa on the Bonavista Peninsula are longer than previously reported from the Avalon Peninsula, withFractofususspindles present in the Trepassey Formation,Bradgatia, Charnia, Charniodiscus, andIvesheadiareaching as high as the Fermeuse Formation, andAspidellaextending into the middle of the Renews Head Formation. the spindles in the Trepassey Formation are comparable to those found mainly in the stratigraphically older Briscal Formation on the Avalon Peninsula.