Endocranial morphology of the extinct Antillean shrew Nesophontes (Lipotyphla: Nesophontidae) from natural and digital endocasts of Cuban taxa

Abstract

This paper describes the endocranial morphology of the extinct genus of Antillean shrews Nesophontes, based on natural and digital endocranial casts extracted from Cuban species. The endocranial casts show developed olfactory lobes without accessory bulbs, an exposed tectum with visible superior colliculi, a large cerebellum and vermis, and a smooth neocortex. Body mass was estimated from skull size to be between 97 and 114 g, yielding encephalization quotients between 0.33 and 0.57. Endocranial casts of Nesophontes are morphologically similar to those of Solenodon more so than to other lipotyphlans such as Sorex, Blarina, Erinaceus, or the afroinsectivoran Tenrec. The morphological similarity to Solenodon, not only in endocranial structures but also in the rest of the skeleton suggests a behavioral analogy between the two genera. The marked superior colliculi, prominent olfactory lobes, and facial musculoskeletal anatomy suggest that Nesophontes was most likely nocturnal and fossorial, relying on hearing, smell, and tactility to forage. Future analysis of the appendicular skeleton can help determine if this genus was solely terrestrial or if it also exploited arboreal habitats. All these morphologies can help elucidate Nesophontes's behavior, ecology, and the osteological variation that is observed in the genus. © Palaeontological Association May 2014.