Unusual extensions of the neural spines in two ichthyosaurs from the Lower Jurassic of Holzmaden

Abstract

Some unusual extensions of the neural spines are reported for two ichthyosaurs from the Lower Jurassic of Germany. These processes are similar to those recently reported for the enigmatic marine reptile Hupehsuchus, from the Middle Triassic of China. There are insufficient data to determine whether the ichthyosaurian processes are homologous with those of Hupehsuchus, nor whether they represent ancestral features that were normally suppressed during ontogeny. The possibility that the processes are artificial rather than natural cannot be discounted.