Recently Miquel et al. investigated the Succineidae from the southern tip of South America and found a new species.
“A new species of Succinea from Santa Cruz Province (Argentina) is described. Succinea argentina sp. nov. is characterized by the following features: a shell of regular growth, 3 to 3.25 whorls, length of 6.0 to 7.15 mm, shell not succineid, opaque walls and conspicuous axial ribs; strawyellow opaque deciduous periostracum; radular formula: 21-9-C-9-21, with central tooth tricuspid, lateral teeth bicuspid and marginal teeth tricuspid; penis with epiphallus, wrapped in a common sheath, without appendices, and formed by two regions: a long proximal region, which is lined by a mucosa with multiple transverse folds, and a short distal region, which opens into the atrium; vas deferens composed of three main regions – preprostatic, prostatic and postprostatic –, entering the epiphallus subterminally, and covered by a mucosa with multiple folds of different sizes; vagina long, thin and convolute; spermatheca globose, with a long duct that opens in the last portion of the vagina; atrium short“.
As with all succineid species the anatomy plays an important role. Nonetheless it is remarkable that the authors diagnose this species morphology as “not succineid”. There are several other related species occurring in this region from which it is, however, clearly different.
Miquel, S.E. et al., 2019. A new species of Succinea Draparnaud from the extreme south of Argentina. – Spixiana, 42: 177-184.