Anhuilong is known from the holotype AGB 5822, a forelimb consisting of a left humerus, ulna, and radius. It is distinguished by the following combination of features: low ratios of the average of the greatest widths of the proximal end, mid-shaft and distal end of the humerus/length of the humerus, total length of ulna to humerus and total length of radius to humerus; the lateral edge of the deltopectoral crest directs caudolaterally, the lateral accessory condyle on the craniodistal edge of humerus is more robust than the medial one, and the cross-sectional shape of the ulna at mid-shaft is elliptical with highest ratio of transverse to craniocaudal diameter among mamenchisaurids.^[1]

Ren et al. (2020)^{[nb 1]} recovered Anhuilong as the sister taxon of Huangshanlong, with the closest relative of this clade being Omeisaurus tianfuensis. The results of their phylogenetic analysis are shown in the cladogram below:^[1]