A recent revision of Stephanorhynchus has split the genus into four.

For more details, read the open-access paper:
Mazur, M. A., & Brown, S. D. J. (2024). A review of the genus Stephanorhynchus White, 1846 (Coleoptera: Curculionidae: Eugnomini), with a description of three new genera and one new species from New Zealand. The European Zoological Journal 91(1): 457-549. https://doi.org/10.1080/24750263.2024.2319789