Hugh Miller’s Reptile Bed and the Mytilus Shales, Middle Jurassic, Isle of Eigg, Scotland

Abstract

Synopsis: The type locality of the Mytilus Shales, the lowest division of the Great Estuarine Series on the Isle of Eigg, is described. A map of the exposures is presented, and the detailed stratigraphy of the beds, which include a bed rich in reptilian bones discovered by Hugh Miller, is expounded for the first time. The outcrop is disturbed by small faults and intrusions and partially obscured, so that the succession has to be constructed from five partial sections. The invertebrate faunas, mainly of brackish-water mollusca, are listed. The Reptile Bed itself, a sideritic shelly limestone, is described in detail. Recent work by others on the reptiles, mainly plesiosaurs, is referred to. The conditions of deposition of the Mytilus Shales and especially of the Reptile Bed are considered and analogies are drawn with the bays of the Florida Everglades.