Dictionary.net

• The fish-lizard, a genus of extinct marine reptiles, uniting some of the characteristics of the Saurians with those of fishes.

1899 - The american dictionary of the english language.
By Daniel Lyons

• n. [Greek] A fossil marine reptile, having an organization intermediate between that of a Saurian and a fish. From specimens found, it has been calculated that the largest of these reptiles were about thirty feet long.

1871 - The Cabinet Dictionary of the English Language