It is classified as a Konservat-Lagerstätten because of the exceptional quality of preservation of the fossils and is dominated by crustaceans; the deposit dates back to the Lower Carboniferous, some 359 to 323 million years ago.
It consists of a layer of dolomitic limestone surrounded by Dinantian mud shales which were formed as a result of the deposit of material in either a delta plain setting or in an inter-distributary bay, where sedimentation occurred because of flood-generated incursions.
The sudden changes in salinity caused mass mortalities of this fauna, and also brought marine species such as orthocone cephalopods, polychaete worms and conodonts, which are also found fossilised here.
Schram in 1979 as Waterstonella grantonensis, named for Dr. Charles Waterstone, keeper of geology at the Royal Scottish Museum, and the location where it was found.
[4] The shrimp bed is also important because it was the first place to provide evidence of the structure of conodonts; this is because these animals were soft-bodied, and only their teeth were suited for preservation under normal conditions.