 "V. a. insulanicus" was proven to be monophyletic, but it is more closely related to "V. baritji" than to other "V. acanthurus".Therefore, "V. a. insulanicus" might represent a distinct species.Wilson and Swan (2010) still accept "V. a. insulanicus" as a valid subspecies of "V. acanthurus", which is easily distinguished from other spiny-tailed monitors by its dark colouration and more-banded pattern.