Pre-Columbian Littorina littorea in Nova Scotia.

Littorina littorea, an abundant northeast North American gastropod, was thought to have been introduced from Europe about 1840. Shells of that species found in ancient Micmac Indian camp sites in Nova Scotia have been radiocarbon-dated as pre-Columbian. Failure of L. littorrea to extend its range southward before 1840 may have been due to oceanographic factors.