Perumegabalanus calziai gen. et sp. nov., a new intertidal megabalanine barnacle from the early Miocene of Peru

Abstract

Living members of the tribe Austromegabalanini are large-sized balanid barnacles (Crustacea: Cirripedia: Neobalanoformes) that live in temperate and cold waters of the Southern Hemisphere. During the Neogene, however, the austromegabalanines also inhabited the Northern Hemisphere, as well as some low-latitude tropical environments. This paper describes a new taxon of austromegabalanines, Perumegabalanus calziai gen. et. sp. nov., from the shallowmarine, nearshore, lower Miocene (19 to 17 Ma, Burdigalian) deposits of the Chilcatay Formation (East Pisco Basin, southern Peru). The shell of P. calziai gen. et. sp. nov. has thick, ornamented, multitubiferous parietes and a vesicular sheath that we interpret as indicative of an intertidal habitat. The compresence, in the early Miocene of southern Peru, of two genera of austromegabalanines (i.e., P. calziai gen. et. sp. nov. and the recently described Austromegabalanus carrioli), supports the hypothesis of an early diversification of this tribe at low latitudes.