The tail of the Jurassic fish Leedsichthys problematicus (Osteichthyes: Actinopterygii) collected by Alfred Nicholson Leeds - an example of the importance of historical records in palaeontology

Abstract

The specimen of the tail of Leedsichthys problematicus, now in The Natural History Museum, London, was one of the most spectacular fossil vertebrates from the Oxford Clay Formation of Peterborough, but as an isolated find it shares no bones in common with the holotype of the genus and species. However, a letter from Alfred Nicholson Leeds and related documents cast valuable new light on the excavation of the tail, indicating that it was discovered with cranial bones, gill-rakers, and two pectoral fins, thereby including elements that can potentially be compared with those of the holotype. The documents also clearly indicate that The Natural History Museum's specimen is not part of the same individual as any other numbered specimen of Leedsichthys as had been speculated on other occasions. The maximum size of the animal represented by The Natural History Museum's specimen was possibly around 9 metres, considerably less than previous estimates of up to 27.6 metres for Leedsichthys. Historical documentary evidence should therefore be rigorously checked both when studying historical specimens in science, and in preparing text for museum display labels.