A weathered limestone outcrop surface shows an impressive array of the large pygidia (tail shields) of the scutelluine trilobite, Ekwanoscutellum ekwanensis. About 10 fan-shaped pygidia are randomly oriented (upside down and rightside up) in an area measuring about 35 cm x 35 cm. Each pygidium features a short, bluntly tapered axial lobe from around which radiate a series of broad, smoothly rounded ribs.

Another accumulation of Ekwanoscutellum pygidia has been partly excavated from the reef margin. About a dozen complete and fragmentary tail shields are visible on the exposed limestone surface. These are randomly stacked on top of each other in an overlapping array; some are concave up (showing the ventral side) and others show the dorsal surface. A mapping compass sits to the right side and provides scale.

A grey, weathered surface of the exposed reef flank shows faint impressions of multiple Ekwanoscutellum pygidia. Sitting on the surface are two examples of freshly excavated tail shields, with multiple overlapping specimens in each. These are creamy brown in colour and contrast sharply with the old exposure. A marking pen at the right of the image is 14 cm in length and indicates how big the individual pygidia are.

An isolated cluster of Ekwanoscutellum pygidia excavated from one of the reef accumulations and photographed in the lab. The largest, almost fully exposed specimen in the lower centre measures 15 cm in axial length, indicating that the complete trilobite would have been at least 25 cm long.

A #TrilobiteTuesday follow-up to my last 2 #Strataday posts on the #Silurian Attawapiskat Fm, #HudsonBayLowlands. A major goal of #fieldwork was documenting & interpreting multiple accumulations of Ekwanoscutellum ekwanensis #pygidia: dozens of large tail shields nested together in #reef hollows!