Archaeonassa Fenton et Fenton, 1937

Emended Diagnosis.—Short, round- to ovoid-shaped or elongated trails or burrows commonly deeper at one end, and may grade into indistinct V-shaped trails; concave to slightly convex furrow flanked by pair of convex ridges, central furrow typically wider than ridges; lateral convex ridges may be smooth or ornamented with oblique to transverse striations or smaller lobes (Fenton & Fenton, 1937a; Buckman, 1994).

Diagnosis Raised, narrow traces, straight to sinuous or gently meandering, having a median groove flanked by rounded ridges. (Remark: Yochelson & Fedonkin, 1997 described the type material of Fenton and Fenton 1937).

Description. Straight to sinuous traces having a median groove flanked by rounded ridges. The flanking ridges are very well developed, and locally display an undulating morphology. In cross-sectional view the median groove commonly displays a V-shaped morphology. Trace width is 6.2-11.6 mm. Maximum length observed is 91.2 mm. Preserved as positive epirelief in fine- to very fine-grained sandstone.