Mesoplodon bahamondi sp. n. (Cetacea, Ziphiidae), a new living beaked whale from the Juan Fernández Archipelago, Chile

Abstract

Mesoplodon bahamondi sp.n. is described from a calvarium collected at Playa Blanca, Robinson Crusoe Island (33°37'S, 78°53'W), off Chile. Cranial characters which differentiate this new species from all congeners include: 1) unique arrangement and shape of bones in the antorbital region, in particular the large size of the jugale; 2) widest known rostrum base, relative to zygomatic width, of any known Mesoplodon skull; 3) the extremely short distance between the premaxillary foramina. Comparisons are made with other species of Mesoplodon, in particular with M. bowdoini, its closest morphological relative, confirming its distinctness. The antorbital region is proposed as useful aid in the identification of Mesoplodon skulls. The possible relationship between M. bahamondi with an unidentified Mesoplodon repeatedly sighted in the eastern tropical Pacific is suggested.