The craniology and relationships of four species of bos 1. Basic craniology: Bos taurus L. and its absolute size

This paper is the first of a series on the craniology of four species of Bos . Here (and in the next paper) Bos taurus in Britain is used to establish a basic craniology for the genus. In the initial sections notes are made on the nomenclature, material available, history, and age assessment of B. taurus . The subsequent section deals with the effects of sex, age and breed on absolute size. The results show that Bos taurus is very variable, particularly in the length of the horncore. Sex influences certain dimensions very greatly, particularly those of breadth. Although the horns of cows are often longer than those of bulls of the same breed the horn cores may be shorter in cows. In studying the effects of age it can be seen that growth rates are initially very high, slowing down at about three years of age. Tooth row length decreases with age and hence it is a particularly unreliable indicator of size. Obviously breed affects size and it has been possible to divide the skulls studied into size groups which correspond well with known body weights.