Deep-water marine Rusophycus and Cruziana from the Ordovician Lotbiniere Formation of Quebec

Abstract

Specimens of Rusophycus isp. and Cruziana isp. preserved on a slab collected from talus of the late Middle Ordovician Lotbiniere Formation exposed at Montmorency Falls, northeast of Quebec City, are figured and described. Post-Ordovician benthic trilobites, in marine scenarios the presumed producers of such ichnotaxa, were restricted to generally shallow-water ecological niches. Older trilobite taxa inhabited a wide spectrum of environments, as also reflected in the occurrence of these ichnotaxa in the Lotbiniere Formation. Occurrence of these ichnotaxa in the Lotbiniere Formation, an undoubted basinal microflysch sequence, suggests that caution should be exercised, when occurring in isolation, with respect to the palaeoenvironmental significance of these ichnotaxa. -from Author