Four new fossil tegulines (Gastropoda: Trochidae) are described from southern Peru [Chlorostoma quipua new species (late Miocene to late Pliocene), Intistoma pirqua new genus, new species (early Pliocene), Cantallocostoma panistostum new genus, new species (late Miocene to early Pliocene), Tegula (s.l.) masiasi new species (early to middle Miocene)], as are Pliocene and Pleistocene occurrences of the extant Chlorostoma atrum (Lesson, 1830), C. luctuosum (d’Orbigny, 1841), Cantallocostoma quadricostatum (Wood, 1828), Agathistoma patagonicum (d’Orbigny, 1835), T. (s.l.) melaleucos (Jonas, 1844), and T. (s.l.) tridentata (Potiez and Michaud, 1838). These data show that the Peruvian chlorostomine group is too ancient to be a Pliocene sister group to Caribbean-Atlantic agathistomines; indicate additional eastern Pacific groups of tegulines exist with roots reaching into the Miocene; and further demonstrate the success of A. patagonicum as a widespread and long-lived teguline in austral waters. A small radiation of Peruvian chlorostomines during the late Pliocene coincided with a molluscan mass extinction event in the Peruvian Faunal Province.
