NEW SPECIES OF JURASSIC BRACHIOPOD ANARHYNCHIA FOUND IN OREGON

Specimens of the rhynchonellide brachiopod genus Anarhynchia from the Jurassic of Central Oregon have been investigated. They were associated with serpentinites and mineralization in the field. This new material, Anarhynchia sp., is considered a new species, distinct from the type species Anarhynchia gabbi originally described from California. Forthcoming geochemical analysis will hopefully establish if the carbonates in which Anarhynchia sp. was found formed in association with serpentinization, and if the brachiopods were part of a chemosynthetic ecosystem. Such ecosystems exist in cold seeps, which are places in which H₂, CH₄, and other hydrocarbons form due to serpentinization of mafic and ultramafic rocks. Bacteria use these to obtain energy and form the basis of an ecosystem.