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 🇨🇦

An outcrop photo of fossiliferous buff-coloured limestone, showing broken sections through an overturned favositid coral colony (across the top of the image) and a rotated domal stromatoporoid on the right. The fossils are grey-white in colour. The coral shows an open porous structure, with individual corallite walls and horizontal tabulae well-preserved. The stromatoporoid shows the dense, finely layered texture typical of these calcareous sponges. A geological hammer in the lower left provides scale.

I missed #SpongeThursday this week, so #FossilFriday is a double header: lower right is a nice stromatoporoid ("stony sponge") & upper centre is a favositid ("honeycomb") tabulate coral. Storm deposit in the Kwataboahegan Fm - early/mid #Devonian (~394 MYA), nr Moosonee #HudsonBayLowland #Ontario 🇨🇦

A broken natural lateral section through a cluster of branching colonial horn corals embedded in grey limestone. The lighter coloured fossils stand out in relief, and show excellent details of internal structures, such as septa and dissepiments.

The same cluster of horn corals seen from above, looking down into the individual large corallites.

A group of three geologists and palaeontologists hiking along a rocky river shoreline, under an overhanging cliff of bedded limestone. The cliff has been undercut by river erosion, and is capped by dense plant growth.

A view at water level across a set of whitewater rapids on a large river. Standing waves and turbulent water mark a sharp drop-off over submerged rock ledge. A large boulder rests atop the ledge about 10 metres offshore. Tall spruce trees stand on the far shore above a cliff of limestone.

Another #FossilFriday #flashback -- this week to 1994 & some beautiful colonial rugosan #corals in the #Devonian (~395 MYA) Kwataboahean Fm. At the aptly named #CoralRapids on the Abitibi River, #HudsonBayLowland, #Ontario 🇨🇦. A dull day for fieldwork, but a brilliant one for #fossils.