Fig. 3From: Middle Triassic gastropods from the Besano Formation of Monte San Giorgio, Switzerlanda-d Worthenia (Humiliworthenia)? aff. microstriata Nützel et al. 2018, Middle Besano Formation, uppermost Anisian. MCSN 3002: a abapertural view, b apertural view, c basal view, and d detail with growth lines on the ramp. e–h Frederikella cf. cancellata (Zardini 1978), Lower Besano Formation, uppermost Anisian. PIMUZ 29952: e apical and f umbilical view, g transversal section, h apical side view. All images have been obtained producing positive silicon casts from negative external moldBack to article page