A horizon with large, massive corals in growth position was discovered in the Paleocene, probably upper Danian, part of the Maastrichtian–Paleocene Lefipán Formation of Chubut (Patagonia, Argentina). All corals belong to one species, the cosmopolitan Haimesiastraea conferta Vaughan, which survived the end-Cretaceous mass extinction. The occurrence of massive corals at this site is exceptional both because of the siliciclastic depositional regime and because of the high palaeolatitude setting. An unusual autecology of this coral and strongly reduced sedimentation rates, were probably the prerequisites for coral growth, but a link to palaeoclimate is less likely.