Slab of bioturbated limestone from hard gray limestone subunit of Worland Limestone

Burrow mottling dominates the appearance of this bioturbated micritic
limestone from the lower part of the Worland Limestone. Dark laminae
produced by algal mats or microbial communities extend part way across
the slab, but these are interrupted by burrow structures. Near the bottom
of the slab between 7 cm and 8 cm on the scale is an elongate dark grain
that is completely surrounded by algal/microbial lamination. Scattered
white specks are crinoid fragments, and there are also a few bivalved
shells (small brachiopods or ostracodes). A shell of the spiriferid brach-
iopod Crurithyris in the lower part of the slab between 4.5 and 5 cm on
the scale shows remarkably well preserved supports (called spiralia) for
the lophophore

View close-up of lamination and burrow structures
View close-up of grain with laminated coating
View close-up of Crurithyris showing spiralia within shell

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