Chronospatial variation of dental size of Holocene Japanese wild pigs (Sus scrofa leucomystax)

Abstract

The lower teeth of the Japanese wild pigs (Sus scrofa leucomystax) from various geographical locations both archaeological and modern were investigated. Buccolingual measurements of the lower third and fourth premolars, and first and second molars are used to compare the regional and temporal differences in dental size of pigs in the Japanese Archipelago.Similar geographical variations in size of Jomon and modern wild pigs in Japan are observed in our study. The size of pigs from northern localities are larger compared to those from southern localities. Populations from Kyushu are distinctively small in dental size compared to the Honshu in both the Jomon and modern populations.A different pattern is observed in the Yayoi samples. The pigs from the Yayoi Period show a west-east cline in their size where the populations in the west being larger than those of east. Interestingly to note is that the size of pigs are significantly different between the sites in the northern Kyushu as well as in the western Honshu. The variation in a single region exceeds the geographical variations observed in the Jomon or in the modern samples. We can supose that most of these individuals were brought in from outside the Archipelago. It is a necessity to understand the variation of the modern and archaeological pigs in the Asian continent in order to further discuss the issue morphometrically.