Problematic marine palynomorphs from the Silurian-Devonian Gaspe Limestones, Gaspe Peninsula, Quebec, Canada

Abstract

The study of the Gaspe Limestones reveals that a varied and rich assemblage of "chitinous" microfossils is present within most samples. The fossil evidence for hydrozoans and pterobranchs is presented relying heavily upon infra-red and scanning electron microscopical studies. Using similar methods, melanosclerites are described, their taxonomic status reinterpreted and their affinity reinterpreted. An extensive ultrastructural study of Chitinozoa biology has lead to an ontogenetic, and phylogenetic reinterpretation. They are concluded to be the extinct representatives of the protozoan sarcodines. The relationship of their preservation to early diagenesis of the substrate are also discussed. A new classification is presented as is the new hypothesis for their extinction at the end of the Devonian. The biostratigraphy of the Gaspe Limestones using chitinozoans is used and the evidence for the Silurian-Devonian boundary is presented as is the discontinuity of the Gaspe Limestones especially for the Roncelles Mbr. The evidence for the Silurian age of a fault block is also discussed.