031220c

A microcoprolite grainstone, a limestone composed chiefly of the fossil fecal pallets of burrowing shrimp, Jurassic Smackover Formation, Alabama. All photos 2.5 mm in the long dimension. Samples from cores between 2 and 3 miles below the surface. Most pellets are Parafavreina ziczac, seen in various orientations. Darker specimens retain more organic material. Relatives of the shrimp that made these pellets are common today in shallow tropical waters, which is why we know who made them.

The squished specimen in the middle was still soft at the time of burial.