Night Monkey - Taxonomy

Taxonomy

Until 1983, all night monkeys were placed into only one (A. lemurimus) or two species (A. lemurinus and A. azarae). Some authors still believe there are only two or three true species, the remaining taxa being subspecies of these. An often-used distinction is an even split of eight species between a northern, gray-necked group (A. lemurinus, A. hershkovitzi, A. trivirgatus and A. vociferans) and a southern, red-necked group (A. miconax, A. nancymaae, A. nigriceps and A. azarae). Arguably, the taxa otherwise considered subspecies of A. lemurinus – brumbacki, griseimembra and zonalis – actually should be considered separate species, whereas A. hershkovitzi arguably is a junior synonym of A. lemurinus. A new species from the gray-necked group was recently described as A. jorgehernandezi. As is the case with some other splits in this genus, an essential part of the argument for recognizing this new species was differences in the chromosomes. Chromosome evidence has also been used as an argument for merging "species", as was the case for considering infulatus a subspecies of A. azarae rather than a separate species. Fossil species have (correctly or incorrectly) been assigned to this genus, but only extant species are listed below.