Edited sentence: Dark Spiny Tree-rat - Echimys saturnus.Echimys vierai.Members of the genera Callistomys, Makalata, Pattonomys, andPhyllomys were all formerly considered part of the genus Echimys.Members of the genus are collectively called Spiny Tree-rats as they are arboreal and have pronounced spines.Pp 1538-1600 in Mammal Species of the World a Taxonomic and Geographic Reference 3rd ed.Reeder eds.Smithsonian Institution Press, Washington D.The genus contains three extant species.White-faced Spiny Tree-rat - Echimys chrysurus.Wilson and D.Woods, C.and C