57. Hiatella arctica (1917)

Hiatella arctica

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

Decade: 1910s


Dawson, J.W., 1893. The Canadian ice age; William V. Dawson, Montreal, 298 p. http://www.biodiversitylibrary.org/bibliography/38902#/summary

Gadd, N.R., 1971. Pleistocene geology of the central St. Lawrence Lowland; Geological Survey of Canada, Memoir 359, 153 p. doi:10.4095/102381

Johnston, W.A., 1917. Pleistocene and Recent Deposits in the Vicinity of Ottawa, with a description of the Soils; Geological Survey of Canada, Memoir 101, 69 p. doi:10.4095/101671

Wagner, F.J.E., 1970. Faunas of the Pleistocene Champlain Sea; Geological Survey of Canada, Bulletin 181, 104 p. doi:10.4095/102325

GSC 175 - CGC 175