METHODS AND MATERIALS

B.E.B. Cameron, J.W. Haggart, and assistants of the Geological Survey of Canada (GSC) collected samples used in this study through several field seasons (1980-1993). Station numbers were assigned to all localities and recorded along with locality coordinates (Table 1). Although many stations were systematically sampled through stratigraphic sections, many stations comprised single samples collected from isolated, structurally disrupted outcrops of uncertain age (Figure 3). The collected bulk samples were ~5 kg each and were processed at the GSC's Pacific Geoscience Centre Paleontology Laboratory at Sidney, British Columbia, using techniques developed at the Geological Survey of Canada (see Johns et al. 2006). Samples were then picked for microfossils at the GSC-Pacific office in Vancouver and isolated specimens mounted on slides. Slides were then delivered to Carleton University for identification and analysis.

Specimens were photographed using a JEOL 6400 scanning electron microscope at the Carleton University Research Facility for Electron Microscopy (CURFEM). For specimens whose chamber arrangements were difficult to discern under the SEM, a Javelin video camera mounted on an Olympus SZH stereo-microscope was used to produce a light photograph. Coarsely agglutinated specimens were embedded in a Lakeside 70 epoxy resin and carefully ground on 15µm wet/dry abrasive paper to expose diagnostic internal test structures.