 They later assigned the Antillean monkeys to the tribe Xenotrichini – the sister group of the tribe Callicebini with extensive anatomical comparisons and by extending their parsimony analysis using PAUP*.They maintained that the monophyly of the Antillean monkeys was still supported in the most parsimonious trees, but in slightly less parsimonious trees, "Aotus" appeared to be linked with "Xenothrix".In July 2009, Walter Pickel found a "Antillothrix bernensis" skull while diving in underwater caves.