1 September 2011 Allometric Comparison of Skulls from Two Closely Related Weasels, Mustela itatsi and M. sibirica
Satoshi Suzuki, Mikiko Abe, Masaharu Motokawa
Author Affiliations +

We conducted an interspecific comparison of skulls from two closely related but differently sized mustelid species, Mustela itatsi and M. sibirica (Mammalia, Carnivora, Mustelidae); a sexual comparison within the latter species showed remarkable size dimorphism. We clarified several differences in skull proportion related to size using allometric analyses and qualitative comparisons. Allometric analysis revealed that the skulls of male M. itatsi (the smaller species) have a relatively long palate; a slender viscerocranium and postorbital constriction; a broad, short, and low neurocranium; small carnassials; and a short mandible with a thin body and small ramus compared to the skulls of male M. sibirica (the larger species). Similar results were obtained when male M. itatsi were compared to female M. sibirica, although the male M. itatsi had a broader viscerocranium than female M. sibirica. A sexual comparison in M. sibirica revealed a larger skull size among the males with a relatively wide viscerocranium; wide postorbital constriction; a slender, long, and high neurocranium; short and wide auditory bullae; short carnassials; and a long and high mandible compared to females. Qualitative comparisons revealed changes in a few characters depending on skull size or with respect to some cranial components in each species. The interspecific differences observed were clearly larger than the intraspecific differences for three qualitative characters. The allometric and qualitative differences detected between these species suggest that each species is not simply the dwarf and/or giant morph of the other, and complicated differences were clarified.

© 2011 Zoological Society of Japan
Satoshi Suzuki, Mikiko Abe, and Masaharu Motokawa "Allometric Comparison of Skulls from Two Closely Related Weasels, Mustela itatsi and M. sibirica," Zoological Science 28(9), 676-688, (1 September 2011). https://doi.org/10.2108/zsj.28.676
Received: 1 December 2010; Accepted: 1 February 2011; Published: 1 September 2011
allometric comparison
M. sibirica
Mustela itatsi
sexual dimorphism
skull morphology
Get copyright permission
Back to Top