A long-standing view holds that Anomalocaris fed on hard-bodied animals, including trilobites. While its mid-gut glands strongly suggest a predatory lifestyle, its ability to penetrate mineralised shells has come under fire in recent years.[18] Some Cambrian trilobites have been found with round or W-shaped "bite" marks, which were identified as being the same shape as the mouthparts of Anomalocaris.[16] At most one species, A. canadensis, is likely to have been capable of eating hard-skeletonized organisms; other species likely preyed on soft-bodied animals.[19]