Geographical Variation of the Skull of the Lesser Mouse Deer

Abstract

ABSTRACT. We examined the geographical variation of the skull size and shape of the lesser mouse deer (Tragulus javanicus) from Laos, Thailand, Peninsular Malaysia, Sumatra, Java, Borneo, Langkawi and some Islands of Tenasserim in Myanmar. Although the influence of the climatic condition on skull size was not confirmed in the mainland populations, the skull became rostro-caudally longer in the populations of Tenasserim and Sumatra because of island isolation effect. The skull size was classified into the following thre e clusters of localities from the matrix of Q-mode correlation coefficients: 1) Langkawi and Tenasserim, 2) Laos and Thailand, 3) Sumatra and Borneo. The skulls in the population of Java belong to the cluster of Langkawi and Tenasserim in male, however were morphologic ally similar to those in the cluster of Borneo and Sumatra. The canonical discriminant analysis pointed out that the Laos and Tenasserim populations were separated from the other ones and that the populations of Sumatra, Java and Borneo were intermingled each other.

Phylogenetic relationships among populations of the mouse deer in the Southeast Asian Region from the nucleotide sequence of cytochrome b gene

“…More recently, Meijaard and Groves (2004) used a combination of external and craniometric features to justify recognition of two additional species from within the T. napu group -T. versicolor from south-east Vietnam and T. nigricans from Balabac Island. They also confirmed our earlier finding (Endo et al 2004b) of morphological differences in T. napu between populations from peninsular Malaysia and the islands of Indonesia. In the Lesser Mouse deer populations, Meijaard and Groves (2004) were unable to find substantial morphological differences between the populations in Laos, Vietnam and East Thailand (subspecies: affinis), and those on Borneo Island (subspecies: fulviventer and ravus).…”

“…Although it is generally agreed that the two species differ in overall size, morphological studies of coat color, body proportions and skeletal morphology generally have failed to provide clear diagnoses of the two taxa (Miller 1900(Miller , 1902(Miller , 1903Thomas and Wroughton 1909;Kloss 1916Kloss , 1918Chasen 1935Chasen , 1940van Dort 1988van Dort , 1989Corbet and Hill 1992). In part, this reflects the presence of geo-graphic variation in size in both species, resulting in overlap between the two species in many external and skull measurements (Lekagul and McNeely 1988;van Dort 1988van Dort , 1989Corbet and Hill 1992;Endo et al 2004b). Van Dort (1989) concluded that the two species are distinguishable only on throat color and from multivariate analysis of the metatarsal bone and femur of adult specimens.…”