Exceptional preservation of Eocene vertebrates in the lake deposit of Grube Messel (West Germany)

Abstract

Less than 2% of Lagerstätten with fossil vertebrate remains have yielded anything more than fragments of jaw material and other bones. One such exceptional deposit is the former oil shale mine of ‘Grube Messel’, located about 30 km south east of Frankfurt am Main. Articulated skeletons of various fish, salamanders, frogs, turtles, lizards, snakes, crocodiles, birds and mammals, as well as several hundred insects and plant remains, have been recovered, particularly during the last decade. The quality of preservation is truly exceptional. In many cases not only are the skeletons articulated, but the outlines of the entire body are preserved as black silhouettes. Sometimes even the contents of the digestive tract are available for investigation. Apart from the fish that formerly lived in the lake, the most frequent fossils found are flying creatures such as birds, bats and insects. Clearly, the lake acted as some kind of trap for these animals. The different modes of preservations are reviewed and the factors involved in this example of special preservation discussed.