Data on the ancient Japanese horse is so scarce that the horse type and the route of entry from the Eurasian Continent have not yet been known. Recently, numerous hoof prints have been discovered at the Shiroi site, Central Japan. The prints were covered with pumice layer which fell in the Kofun period (6th century AD). Remains of the horse itself have not yet been found at this site. We have been trying to estimate the withers height of the horse by measuring the hoof prints and by analysing them. We have come to the conclusion that the Shiroi horse is the same medium-type as the native Kiso horse which has about from 125 cm to 135 cm withers height. Our analytical procedure is as follows: 1) Measurement and analysis of approximately 2,300 good samples of the hoof prints from among 40,000 samples. The most frequent statistical class of forefoot hoof print width is from 106 mm to 110 mm. 2) Experimental measurement of the hoof and hoof print of a native horse. We realize very little difference exist between the size of the hoof and of the hoof print. 3) Examining of the interrelationship between the hoof size and withers height in the native horses and Thoroughbred. Our conclusion is that they are closely interrelated. 4) Comparing the hoof width of the Shiroi horse with the modern horse. The modern horse in Japan can be classified into three types: the native small-type horse (Tokara horse; average width of forefoot hoof print 85 mm), the native medium-type (Kiso horse; average width of forefoot hoof print 105 mm), and the recent large-type from abroad (Thoroughbred; average width of forefoot hoof print 132 mm).
Japan, ancient, horse, hoof-print, withers-height, estimation.