Early Cambrian problematic fossils near June Lake, Mackenzie Mountains, N.W.T.

Compressed cylindrical remains of probable trace fossil affinities are described under the taxon Palaeophycus ferrovittatus n. sp. The structures are preserved as ornamented, reddish brown, rectilinear to curvilinear ribbons of iron oxide several centimetres long, several millimetres wide, less than 1 mm thick, and surrounded by an argillaceous envelope. They occur along bedding planes in greyish olive weathering mudstone interbedded with glauconitic quartz sandstone in the Backbone Ranges Formation straddling the Precambrian–Cambrian boundary. They are associated with other fossils similarly preserved by iron oxides, including cf. "Helminthoidichnites? meeki" Walcott and Planolites montanus Richter.