TL;DR: The authors' data show that the molecular distances among the four gibbon subgenera are in the same range as those between Homo and Pan, or even higher, and it is proposed to raise all four gibbonsSubgenera to genus rank.
TL;DR: The present data are consistent with the division of Hylobatidae into four distinct clades, provide the first genetic evidence for all the species relationships within Nomascus, and call for a revision of the current relationships among the species within HylOBates.
TL;DR: The generic nomen Bunopithecus is not applicable to hoolock gibbons, and a new generic name is supplied, list the characters and content of the genus, and compared to the other 3 genera of the Hylobatidae.
Abstract: Contrary to usual practice, the generic nomen Bunopithecus is not applicable to hoolock gibbons. We recount the history of its application and explain why it is spurious. We supply a new generic name, list the characters and content of the genus, and compare it to the other 3 genera of the Hylobatidae.
TL;DR: Gibbons are small arboreal apes inhabiting the rainforests of South-East Asia, Northwest India and Bangladesh and under dispute, as the status of several taxa as species or subspecies is uncertain.
Abstract: Gibbons are small arboreal apes inhabiting the rainforests of South-East Asia, Northwest India and Bangladesh (Carpenter 1940; Chivers 1977). The taxonomy of gibbons is under dispute, as the status of several taxa as species or subspecies is uncertain. Within the family Hylobatideae, there are four genera of gibbons: Bunopithecus (hoolock gibbon), Hylobates, Nomascus (crested gibbons) and Symphalangus (siamangs), and at least 12 species (Brandon-Jones et al. 2004). Apart from the sympatric Hylobates agilis/Hylobates lar and siamangs in Sumatra and peninsular Malaysia, gibbons are allopatric (Leighton 1987; Reichard and Sommer 1997). Some hybrids have been found within the genus Hylobates, including populations in Borneo (Hylobates albibarbis and Hylobates muelleri: Mather 1992), in Thailand (H. lar and Hylobates pileatus: Brockelman and Gittins 1984) and in peninsular Malaysia (H. lar and H. agilis: Brockelman and Gittins 1984). The Bornean agile or southern gibbon (H. albibarbis) occurs in southern Borneo, between the Kapuas and Barito rivers (Brandon-Jones et al. 2004). Its taxonomic status is unclear, but recent molecular evidence identifies it as a separate species, rather than a sub-species of H. agilis (Brandon-Jones et al. 2004; Geissmann 2007; Groves 2001).
TL;DR: Revising Groves's taxonomy of 1972, it is proposed that hoolock, along with the fossil species sericus, occupy a subgenus, Bunopithecus, and the genus Hylobates would thus contain four subgenera: Bunopitalcus, HylOBates, Nomascus, and Symphalangus.
Abstract: The recent discovery that the hoolock gibbon (Hylobates hoolock [Harlan, 1834]) has a karyotype distinct from all other hylobatids provides a new and strong motive for revising gibbon taxonomy and establishing hoolocks in a separate, higher taxon. Revising Groves's taxonomy of 1972, we propose that hoolock, along with the fossil species sericus, occupy a subgenus, Bunopithecus. With the newly added taxon, the genus Hylobates would thus contain four subgenera: Bunopithecus, Hylobates, Nomascus, and Symphalangus.