Morphometric evidence for the differentiation of the Himalayan wolf Canis lupus chanco (Canidae; Carnivora)

Abstract The taxonomy of wolves ( Canis sp. complex) is under increasing scrutiny due to molecular evidence revealing the existence of multiple cryptic lineages. Among these, the Himalayan wolf ( Canis cf. lupus chanco ), native to the Tibetan Plateau and the Himalayas, represents one of the most ancient lineages in Eurasia. Its morphological distinction from grey wolf populations remains poorly understood. In this study, we evaluated the morphological differentiation of the Himalayan wolf by analyzing specimens from museum collections using linear and 2D geometric morphometrics. Our comparative analysis included skulls from various wolf populations across Eurasia, grouped according to known genetic lineages. Although linear measurements failed to reveal clear diagnostic features, geometric morphometric analysis indicated that Himalayan wolves possess a shorter muzzle and wider zygomatic arch than other populations. These traits may reflect adaptations to their environment and prey preferences. However, the overlap with other wolf populations was significant, and cross-validation analyses showed low reclassification rates, indicative of morphological conservatism within Canidae. Moreover, several museum specimens previously labeled as Himalayan wolves were misidentified, complicating the taxonomic assessment. Our findings provide support for the subtle morphological distinctiveness of the Himalayan wolf, though further integrative studies incorporating genomic and 3D modeling approaches are required to clarify the taxonomic status of this group.