Slugs evolved from snails more than a dozen separate times. ... Slugs evolved from snails by reducing the size of the shell and internalizing it (yes, most slugs have an internal shell), and there are likely to be consequences of reducing the shell.

Are slugs and snails related?

Snails and slugs are both part of the same class of creatures called gastropods. ... The majority of snails and slugs, though, live in water. The most obvious difference between snails and slugs is the fact that snails have shells. A snail's shell is like a home it carries around on its back.

What did a snail evolve from?

According to fossil records, the earliest gastropods lived in the ocean and possibly appeared during the Cambrian period. From this, the mollusks of the genera Strepsodiscus and Chippewaella developed to become the most primitive snails.