#Snails are primarily marine #mollusks. According to current hypotheses, the #sistergroup might be #Cephalopoda plus #Scaphopoda (Link below) . One #Apomorphy, i.e. evolutionary new acquisitions of the stemspecies, is the #asymmetrical #shell that is wound in one direction, which is due to a #torsion of the #mantle and visceral sac.
The species in my #photos is #Cornu #aspersum from Italy. #biodiversity,
© #StefanFWirth Berlin 2025

Reference

Sumner-Rooney et al. (2015):
https://doi.org/10.1111%2Fede.12164

The #terrestrial #pulmonate #gastropods (#Stylommatophora, Gastropoda) have two pairs of #retractile #tentacles, an #apomorphy (#evolutionary innovation of the stem species) of the higher taxon Euthyneura. The rear pair of tentacles is elongated and has #eyes at its tips.
My photos show them in a close #macro shot using the Mediterranean #snail #species #Cornu #aspersum (#Helicidae).
#biodiversity #evolution
© #StefanFWirth Berlin 2024

Photos
C. aspersum, 2020, New edit 2024 © S. F. Wirth

Some six or so years since "Jeremy" aka "shellebrity snail" , I might finally have a line of left-coiling or sinistral garden snails!! Hoping these 3 virgins just emerging from hibernation, will produce lefty babies. Then can finally get doing the #genomics #asymmetry #chirality #snails #cornu #leftysnail #snaillove