The snailosaurus was a large animal lifeform native to the planet Ferenginar. The snailosaurus was believed to have become extinct sometime before Earth's 19th century, and their fossilized shells were often found on the plains of Splort.
In one version of "The Story of Ving and Ding", the parents of Ving and Ding were killed by a herd of rampaging snailosauri.
A single snailosaurus reappeared during the peak of Ferenginar's wooly slug herding industry, and endangered the livestock of slugboy named Nix. After devouring numerous wooly slugs and Ferengi, this snailosaurus was killed choking on the thighbone of a burly slugboy. (DS9 reference: Legends of the Ferengi)