Abstract
Varanus (Soterosaurus) monitors recently received increased scrutiny from herpetologists, resulting in identification of previously unrecognized morphologic and genetic diversity. These advances rendered Varanus salvator salvator as one of the most narrowly distributed monitors, because most populations are reassigned to existing or newly identified species. No diagnostic skeletal characters are known for those species. Two skeletonized specimens of the recently named Varanus palawanensis are in the collection of the U.S. National Museum of Natural History, but are labeled V. salvator. Here, I offer some observations on those skeletons, make comparisons with some other Varanus(Soterosaurus) monitors, and update the diagnosis of the species with some probable osteological autapomorphies. Varanus palawanensis differs from other Varanus (Soterosaurus) in possessing a unique combination of character states. The premaxilla extends to the level of the frontal, the frontal and parietal lack dermal sculpturing, the lacrimal anteroposteriorly narrow, the vidian canal entirely within the parabasisphenoid, and the anterostapedial process is tab-like. I contend that species should be holophyletic even in the face of taxonomic upheavals created by newly identified diversity.
