they argued that A. paniscus was the basal sister taxon to all other spider monkeys and that A. hybridus was closely related to a clade formed by A.fusciceps/A.eoffroyi and A. chamek/A marginatus.They also argued that A. chamek and A.marginatus did not represent different groups, at least based on the mitochondrial
regions sequenced in their study, while A. hybridus was suggested to be a unique phylogenetic lineage. Finally, Collins and Dubach 2000b) concluded that Ateles geoffroyi and A. fusciceps robustus were closely related sister taxa, and they thus considered them to belong to the same species but different subspecies (Fig. 1)(Collins and Dubach, 2000b).