New species of the ground sloth Parocnus from the late Pleistocene-early Holocene of Hispaniola

Abstract

Parocnus dominicanus sp. nov. represents a new species of megalonychid ground sloth from the Altagracia Province of southeastern Dominican Republic. Specimens of multiple individuals, including one associated partial skeleton, were recovered from two separate underwater caves in the Parque Nacional del Este through collaborations with museums and cave divers between 2009–2013. Parocnus dominicanus sp. nov. is distinguished by its small size compared to that of P. serus, with percent differences in limb element lengths ranging from 13−24%. Numerous cranial and post-cranial elements also exhibit morphological character states that are not attributable to size variations. The recovery of multiple individuals within each locality demonstrates a size dimorphism, possibly sexual, which parallels patterns exhibited by P. serus. The two species are also geographically distinct, with no examples of co-occurrence at any localities to date. Parocnus dominicanus sp. nov. and P. serus share character states that are distinct from those of the Cuban species, P. browni, and which suggest differential usage of the forelimb. The exact age of the specimens described here is unknown, however, Parocnus has been dated to the Holocene in Haiti. http://zoobank.org/urn:lsid:zoobank.org:pub:12E495D3-E261-4522-9854-D3B4C2D5FFB8

Keywords

• paleontology
• Dominican Republic
• Xenarthra
• Pilosa
• Megalonychidae
• taxonomy