Hadroklonis tegula shares the same wide tile-like surface, curved lateral sides, and large aboral indentation as its close relative H. imbrex. Exhibiting a smaller oral groove, H. tegula is also about 2/3 as thick, and weighs substantially less, at a mere 1.6 grams. A white specimen was originally discovered by A. Welby (FORC) on a bag of carrots imported from Canada. C. Huning (DWORC) subsequently discovered white and dark green thalassinus color morphs in a horde collected in Ontario, Canada.