Hiatella arctica is the most common fossilized shell species found in the coarse-grained nearshore sediments of post-glacial seas such as the Champlain Sea, which covered the Ottawa and St. Lawrence valleys 12,000 years ago. This mussel-like creature was a filter feeder that lived attached to stones from below tide level to a depth of 30 to 50 metres.
The fossil is so common that early investigators of Quaternary geology such as the Geological Survey of Canada’s W.A. Johnston, in 1917, used its former species name, Saxicava rugosa to designate Champlain Sea sand and gravel. Indeed, the descriptive name “Saxicava sands and gravels” persisted in the scientific literature until the 1960s, at which time a new generation of Survey scientists, such as Nelson Gadd and Frances Wagner, led the way toward a much more comprehensive understanding of Champlain Sea events and faunas.
Category: Rocks, Fossils, Minerals and Meteorites