Anorrhinus is a genus of hornbills (family Bucerotidae) found in forests of Southeast Asia (just barely extending into adjacent parts of India and China). They are social and typically seen in groups, but only the dominant pair are believed to breed, while other group members act as helpers.
Taxonomy This genus is sometimes limited to the bushy-crested hornbill, in which case the two remaining species, which are sometimes considered conspecific, are placed in the genus Ptilolaemus. A molecular phylogenetic study published in 2013 found that Anorrhinus was sister to a clade containing the genera Anthracoceros and Ocyceros.
The genus contains three species: Image Scientific name Common name Distribution Anorrhinus austeni Austen's brown hornbill northeastern India and south to Vietnam and northern Thailand Anorrhinus tickelli Tickell's brown hornbill or rusty-cheeked hornbill Burma and adjacent western Thailand Anorrhinus galeritus Bushy-crested hornbill Brunei, Indonesia, Malaysia, Myanmar, and Thailand
References
Kemp, A. C. (2001). Family Bucerotidae (Hornbills). pp. 436–523 in: del Hoyo, J., Elliott, A., & Sargatal, J. eds. (2001). Handbook of the Birds of the World. Vol. 6. Mousebirds to Hornbills. Lynx Edicions, Barcelona.