Micro snails
Also known as micro mollusks because it sounds more sciency.
Micro snails are found worldwide, mostly as aquatic species, though as you may have guessed, there are plenty of fully terrestrial species. This includes the world's smallest terrestrial snail, which, if you're a micro snail, was always probably going to be on the cards. So far, as of early 2022, the tiniest title goes to a 0.6-0.68mm snail called Angustopila psammion from northern Laos, having wrenched the title from the foot of another Angustopila species.
Regenerating bush, Tairua, New Zealand Feb 2016
Micro snail, Compton Dundon, February 2019
Cochlicopa sp. under stones, East Portlemouth, S Devon, UK Sept 2016
Micro snail, Koper, Slovenia April 2017
Micro snail from the wet tropics, Northern Queensland, Australia
Micro snail, Koper, Slovenia April 2017
Carychium sp. micro snail, Wookey Hole woods, Somerset, UK Jan 2017
Slender Herald snail, Carychium tridentatum, Slovenia, April 2017
Merdigera obscura micro snail, East Prawle, S Devon UK Sept 2016
Acanthinula aculeata, micro snail, UK
Above is Acanthinula aculeata, a common and rather beautiful micro snail across Northern Europe.
Terrestrial micro snails don't just wander about outside. There are some species that are adapted to cave life like the Zospeum species below from Slovenia, feeding on the clay substrate. They are known as glass snails and are transparent and completely blind.
Zospeum species micro snail
Zospeum micro snail
