ichthyosaur
Concise Oxford English Dictionary © 2008 Oxford University Press:
ichthyosaur /ˈɪkθɪəsɔː/ (also ichthyosaurus /ˌɪkθɪəˈsɔːrəs/)
▶noun a fossil marine reptile of the Mesozoic era, resembling a dolphin with a long pointed head, four flippers, and a vertical tail.
'ichthyosaur' also found in these Oxford entries:

