I think most newts eat snails, I have found empty shells of ramshorn snails in all my aquatic setups, I have witnessed both Pleurodeles waltl, Paramesotriton fuzhongensis and some other species eat them. The Paramesotriton fuzhongensis had much more trouble getting them out than the Pleurodeles. The Pleuros eliminated every snail I put in their tank within hours while the Paras just seem to eat one every now and then.