Lorises (family Lorisidae) are primates of the suborder Strepsirrhini. They belong to the infraorder Lorisiformes, together with their sister group, the Galagidae – galagos from sub-Saharan Africa. The systematics of the family Lorisidae have been long debated. Currently two subfamilies are recognised: Perodicticinae, including the two African genera Arctocebus (angwantibos) and Perodicticus (pottos), and Lorisinae, including the two Asian genera Loris (slender lorises) and Nycticebus (slow lorises) (Mittermeier et al., 2013; Rasmussen and Nekaris, 1998; Rowe and Myers, 2016) (1971) based on a series of craniodental features, and, more recently, supported by a cladistic analysis by Rasmussen and Nekaris (1998). Simpson (1967), however, identified several similarities between the two robust forms, Nycticebus and Perodicticus, and the two small-bodied, slender forms, Loris and Arctocebus. A cladistic analysis on craniodental data by Schwartz and Tattersall (1985) supported these two reciprocal monophyletic clades, but other morphological studies failed to identify a clade including both Perodicticus and Nycticebus (Masters and Brothers, 2002). To further complicate the taxonomy of this primate group, karyological studies conducted in the 1970s identified two alternative groups based on the number of chromosomes: Perodicticus and Loris share a diploid number of 2n = 62, while Arctocebus and Nycticebus exhibit a diploid number of 2n = 52 (although some populations of Nycticebus have 2n = 50) (de Boer, 1973; Masters et al., 2005).