TheGranton Shrimp Bed is afossil-bearing deposit exposed on the southern shore of theFirth of Forth nearEdinburgh, in Scotland. It is classified as aKonservat-Lagerstätten because of the exceptional quality of preservation of the fossils and is dominated bycrustaceans; the deposit dates back to theLower Carboniferous, some 359 to 323 million years ago.[1]
The Granton Shrimp Bed is located on the south shore of theFirth of Forth about 3 km (2 mi) from the centre of Edinburgh. It consists of a layer ofdolomitic limestone surrounded byDinantian mud shales which were formed as a result of the deposit of material in either adelta plain setting or in an inter-distributary bay, where sedimentation occurred because of flood-generated incursions.[1]
The shrimp bed resulted from the periodic inundations of marine water into stagnantlagoons, each incursion leaving a lamina of limestone rich in the fossils of soft-bodied marine invertebrates and other animals. These conditions of fluctuating salinity seem to have created a suitable habitat for an assemblage of shrimp-like crustaceans, fish,bellerophonts,conchostracans andostracods. The sudden changes in salinity caused mass mortalities of this fauna, and also brought marine species such asorthocone cephalopods,polychaete worms andconodonts, which are also found fossilised here.[2]
The Granton Shrimp Bed was first brought to the attention of the scientific community by D. Tait in 1923.[3] He stated that a common crustacean fossilised in the bed wasTealliocaris, but that there were other species there new to science. One of these, the commonest shrimp in this community, was subsequently described byF.R. Schram in 1979 asWaterstonella grantonensis, named for Dr. Charles Waterstone, keeper of geology at theRoyal 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 ofconodonts; this is because these animals were soft-bodied, and only their teeth were suited for preservation under normal conditions.[5] Other unique soft-bodied animals were also found in the bed. The small number of fossils with shells were not decalcified, and the lack ofbioturbation suggests that the sediment was largely lacking in oxygen. The exceptional state of preservation suggests that the assemblage of fossils is likely to represent the original community and not just some elements of it.[1]
55°58′50″N3°15′36″W / 55.98056°N 3.26005°W /55.98056; -3.26005