 The larger "H. sicarius" and "H. mentalis" had very large upper canines and a massive flange at the front of the lower jaw.An adult specimen of "Hoplophoneus" discovered in Badlands National Park, South Dakota, in 2010 by paleontologist Clint Boyd et al.was found to have bite marks on its skull from the teeth of another adult individual of "Hoplophoneus".