This taxon is Not Recognised as a species by BirdLife International.
Aulacorhynchus sulcatus and A. calorhynchus (del Hoyo and Collar 2014) were previously lumped as A. sulcatus following Sibley and Monroe (1990, 1993).
BirdLife International (2016) Species factsheet: Aulacorhynchus sulcatus. Downloaded from http://www.birdlife.org on 03/12/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 03/12/2016.