Article: A reinterpretation of ichthyosaur swimming and buoyancy

A new functional analysis of the reversed heterocercal caudal fin of ichthyosaurs suggests that its function, other than propulsion, was not control of buoyancy, but to produce powerful downwards pitching moments. These moments were used to initiate manoeuvres, to dive after breathing at the surface, and, in one form, to feed. This model is of potential value in analysing the palaeobiology and evolution of ichthyosaurs and other marine reptiles with similar caudal fins.