Nereites (trace fossil) missouriensis (Weller, 1899)

Description.-Intergenic or endogenic linear burrow made in regular and planar or irregular and nonplanar or planar meander patterns. The convex hyporelief, Nereites view, is a series of regular or irregular biserially arranged lobes and pustules. The concave epirelief, Phyllodocites view, consists of a median furrow with lobes on both sides. The median furrow is 4 to 5
mm wide and has a rounded bottom. Narrow ridges, more or less regularly spaced and in clusters of 3 or 4 and bowed in the same direction, cross the median furrow and continue a short distance along the sides. Forward movement is implied as opposite the direction of bow of the peristaltic furrow ridge

Irregularly meandering, horizontal endichnial structure in a fine-grained sandstone bed. It displays a well expressed central zone, which is composed of crescent menisci and poorly marked side zones. The central zone is 2–5 mm wide. The menisci are intact, light-filled, 1–5 mm wide. The side zones are poorlymarked by color changes and seen only locally. Each zone is 1–3 mm wide. Their margins are more or less even. The central zone can be massive in some specimens.

This trace fossil displays characteristic features of Scalarituba Weller, 1899, which was included in Nereites (see Uchman 1995). Nereites is a typical pascichnion produced by an unknown tracemaker (see discussion by Rindsberg 1994; Uchman 1995 ; Mangano et al. 2002).

A straight, biserial row of circular knobs preserved in hyporelief in dark greyish-green micaceous shale. Preserved part of the row is 18 mm long and 1.7–1.9 mm wide, bearing 22 knobs altogether.