Composite skeletons of Ichthyosaurus in historic collections

Abstract

Many collections of Lower Jurassic ichthyosaurs from the U . K . include historic specimens collected during the 19th century , and often with poorly known origins . Here we describe nearly complete skeletons of the Lower Jurassic genus Ichthyosaurus that are probably composites or that , at least , require further examination to assess their authenticity . Specimens from the Thomas Hawkins and Charles Moore collections , in particular , should be examined carefully to determine if the entire specimen is a single individual . The most common elements added to skeletons of Ichthyosaurus are whole or partial forefins , hindfins , or posterior portions of the vertebral column . Historic and more recently collected specimens can also have reconstructed or rearranged portions , sometimes done so expertly that they are barely noticeable , if not for documentation in museum records . Composite , rearranged , and reconstructed specimens can provide valuable morphological data once the added or altered portions are recognized .