Composite and compound ichnotaxa: A case example from the Ordovician of Quebec, eastern Canada

Deep‐water strata of the Lower Ordovician of the Lévis Formation (Middle Cambrian‐lower Middle Ordovician) exposed in and around the Lévis‐Lauzon area of southern Québec, eastern Canada, contain a well preserved ichnofauna dominated by simple horizontal burrows of Planolites Nicholson, Alcyonidiopsis Massalongo and the fecal pellet Tomaculum Groom. The numerical increase in abundance of these ichnotaxa through coarsening upward (Logan) cycles developed within the sequence lends support to previous interpretations of such cycles as records of progressive upward changes (increase) in redox conditions in response to lowstands of sea level. Planolites, Alcyonidiopsis and Tomaculum occur as a continuum of forms developed in one of three ways. First, each may occur as individual and discrete ichnotaxa. Second, they may occur as composite…