An irregularly shaped slab of buff coloured limestone features in the upper left a large, flat dorsal (brachial) valve of a Strophomenida brachiopod. The valve is approximately semicircular in outline and measures about 8 cm wide across the essentially straight hinge line. Low slightly curved ribs radiate from the valve apex to the shall margin. Faint concentric ridges mark the former valve outline at earlier growth stages. To the right of the brachiopod is a lengthwise cross section through a curving solitary rugosan coral. Other fragmentary fossils are present on the same surface. A scale in the lower right is graduated in millimetres.

A big #brachiopod dorsal valve for #FossilFriday. This #Devonian (~393 MYA) #strophomenid measures about 8 cm across the straight (=strophic) hinge. Bonus appearance = longitudinal section thru' a solitary rugosan #coral to the right. Kwataboahegan Fm, Kwataboahegan R, #HudsonBayLowland, #Ontario 🇨🇦