Basal terrestrial deposits in the Cambrian-Ordovician Nepean Formation (Potsdam Group) near Kingston, Ontario, contain arthropod-produced trackways that extend the record of the first arthropod landfall back by as much as 40 m.y. The presence of large, simple cross-beds and of wind-produced structures, including adhesion ripples and wind-ripple lamination, indicates that the host strata were deposited in an eolian dune field, probably in a marginal-marine setting. The trackways were preserved mainly as undertracks and record the activities of large, amphibious arthropods, possibly euthycarcinoids.

You do not have access to this content, please speak to your institutional administrator if you feel you should have access.