'Ichthyosauri' definitions:

Definition of 'Ichthyosauri'

From: GCIDE

Ichthyosaurus \Ich`thy*o*sau"rus\, n.; pl. Ichthyosauri. [NL., fr. Gr. 'ichqy`s, -y`os, a fish + say^ros a lizard.] (Paleon.) An extinct genus of marine reptiles; -- so named from their short, biconcave vertebr[ae], resembling those of fishes. Several species, varying in length from ten to thirty feet, are known from the Liassic, O["o]litic, and Cretaceous formations. [1913 Webster]