Original paper

A Speiballen from the Lower Jurassic Posidonia Shale of South Germany

Thies, Detlev; Hauff, Rolf Bernhard


A Speiballen (regurgitated compacted mass of indigestible stomach contents) from the Lower Jurassic Posidonia Shale of Ohmden, South Germany contains remains of four specimens of the actinopterygian Dapedium sp., the specific identity of which remains obscure, and a lower jaw of a specimen identified as Lepidotes sp. A list of five suitable characters is proposed to distinguish fossil Speiballen containing specimens from other vertebrate fossils. Large, potentially piscivorous animals in the Posidonia Shale ecosystem comprise chondrichthyans (Hybodus), other actinopterygians (pachycormiforms) and marine reptiles (crocodilians, ichthyosaurs, plesiosaurs). Only juvenile ichthyosaurs (Stenopterygius) are known to have preyed on Dapedium. Available data are, however, insufficient to clearly identify the Speiballen producer. The heavy scale armour of basal neopterygians such as Dapedium undoubtedly hampered digestion of these fishes and in this way provided additional protection against predators.