Late Cretaceous-early Tertiary gastropods from southwestern Patagonia, Argentina

Abstract
The continuous sequence of Maastrichtian to Paleocene sediments exposed in the Sierra Dorotea area in southwestern Santa Cruz (Argentina) contains a rich molluscan fauna with many elements characteristic of the Weddellian Faunistic Province. The presence in this fauna of genera such asTaioma, Heteroterma, Fyfea, Zemacies, andPriscaphandersuggests close affinities with faunas of similar age from New Zealand, further supporting the existence of continuous shallow-sea conditions along the southern margin of the Pacific Ocean during the end of the Cretaceous and beginning of the Tertiary. In this paper 25 species are described, of which six are new:Pseudofax costellatusn. sp.,Taioma patagonican. sp.,Heteroterma elegansn. sp.,Fyfea beuin. sp.,Priscaphander sanjosensisn. sp., andPriscaphander bracacciniin. sp.