Lomax, D.R., Sachs, S. & Hall, A. (2022) The ultimate ‘Iffyosaur’ – an unusual ichthyosaur composite containing British and German material of different geological stages. Paludicola 14(1): 32-42.
—Composite fossils can distort our evaluation of the morphology and variation of a species if unrecognised or misidentified. Many Early Jurassic ichthyosaurs collected during the 19th century have been identified as composites, but the problem is not restricted to historic specimens. More recently collected material, including some specimens for sale on the fossil market, are also composites or have been modified. One such specimen (RNHM F5672), said to be from the Lower Lias of Dorset, England, appears to be an almost complete skeleton, but comprises at least three individuals along with a carefully reconstructed and carved skull, and an apparent replica coracoid and forefin. The forefin, if a cast of a genuine specimen, shows a unique set of characters not previously observed in any ichthyosaur. Additionally, various caudal and dorsal vertebrae of indeterminate ichthyosaurs were pieced together to give the appearance of a complete, articulated vertebral column. One authentic block, containing the hindfins, the pelvic girdle and some ribs, can be assigned to Ichthyosaurus conybeari, based on characters of the hindfins. It comes from the Lower Jurassic (Sinemurian) of the Charmouth-Lyme Regis area, Dorset. The entire ‘skeleton’ is set into a large block of matrix which is from the Lower Jurassic (Toarcian) Posidonia Shale of Holzmaden, Germany. Therefore, this fossil represents a composite of material from multiple specimens belonging to perhaps two different genera, collected from two different countries and from two different geological stages.
