This species was described based on a partial skeleton collected on July 26,1977 at Barbers Point, Oahu by Storrs L. Olson. The bones were in perfect condition. The partial skeleton of this bird was found on the floor of the cavern near the bones of a specimen of C. impluviatus. Bones of this species were also found at Moomomi dunes and Ilio Point, Molokai. The Latin name ,viriosus, means strong or robust and refers to the larger size of this species compared to C. hawaiiensis. C. viriosus was described as a large species of Corvus with a long, straight bill.

The most obvious way to distinguish the three Hawaiian species of Corvus is by bill shape C. hawaiiensis with a short, moderateley arched bill; C. impluviatus with a high, impressively arched bill; and C. viriosus with a long, relatively straight bill. The authors of Descriptions of 32 new Species of Birds from the Hawaiian Islands write," Our impression is that the Hawaiian crows probably did not arise from Near arctic ancestors but may very well have been derived from Australasia, much like Chasiempis and the Hawaiian Meliphagidae.

Please do what you can to save the native Hawaiian forest bird species that remain.