These are photos of a live Paeniscutalus crenellus (Philippi, 1867), also known under its junior synonym names Megalobulimus (Microborus) incarum Pilsbry, 1944, and Strophocheilus (Microborus) tenuis Haas, 1955. This species was hitherto classified as Thaumastus (Paeniscutalus), but in my DNA research it showed clearly to be completely separate on a basal branch in the Orthalicoidea.
This ‘living fossil’ occurs on the western slopes of the Andes in Peru, where it has been found from Dept. La Libertad south to the southern part of Dept. Lima (Breure & Mogoll??n, 2010).
Breure, A.S.H. & V. Mogoll??n Avila, 2010. Well-known and little-known: miscellaneous notes on Peruvian Orthalicidae (Gastropoda: Stylommatophora). – Zoologische Mededelingen Leiden 84: 15-35.