From tolweb Walvisteuthis rancureli and W. youngorum were originally placed in a new genus, Callimachus, by Bolstad (2010) in her review of the Onychoteuthidae. She was skeptical that the peculiar Walvisteuthis virilis that had originally been placed in its own family, was an onychoteuthid. The latter had some very peculiar features and was only known from two mature males. Vecchione et al. (2015) in their description of Walvisteuthis jeremiahi, reviewed the position of the genus in light of new data and concluded that the peculiar features of W. virilis were due to morphological changes related to maturity and placed Callimachus as a junior synonym of Walvisteuthis.