How large were aurochs cows?

When talking about the size of the aurochs, we mainly talk about the size of male individual, because the upper size limit of the species is of particular interest. The size of female aurochs, however, should not be overlooked. The size of aurochs cows also tells us about the extent of the sexual dimorphism in the aurochs. 

Aurochs bull and cow. Based on the Lund bull and the Cambridge specimen. It is a rather old reconstruction of mine, I still consider it accurate except for the raised pelvis in the bull and that the horn tips do not face inwards enough

I already did a post on the size of the aurochs in 2013 which was very male-based. It has to be noted that the size of the aurochs varied along its geographic range and also geologic age. Focusing only on the European subspecies, Bos primigenius primigenius, the individuals from the north were larger than from the south, and Pleistocene specimen were larger than Holocene specimen (which might be of anthropogenic cause). The largest credible size estimate for males I found in the literature is 2 metres (Boessneck 1956). Calculating the withers height of the individual with the largest skull ever found (91,2 cm, see Frisch 2010), based on the more or less complete Sassenberg bull (which already is a large-headed specimen) results in a height of roughly 215 cm. The smallest size given for a European aurochs bull that I found in the literature was 154 cm withers height, for a specimen from Denmark (Kysely 2008). Considering soft tissue and hooves in the living animal, we can add about 5 to 10 centimetres to the height of the skeleton. Thus, the size of aurochs bulls in Europe may have varied from 160-200cm or even more. 

But how large were the cows? 

Van Vuure 2002 and 2005 gives an average cow size of 150 cm. The Cambridge specimen, which may or may not be a cow, measures 145 cm (Frisch 2010), what means that in live it must have been between 150 and 155 centimetres tall at the withers. The average size for Danish cows is given 145 cm, accompanied by 160 cm for the bulls (Kysely 2008). The smallest Danish cow was 139 cm tall, the largest 153 cm (Kysely 2008). The smallest cow specimen morphologically assigned to the aurochs is a cow with a withers height of 132 cm (Schibler et al. 2014) meaning 137 to 142 cm in life. For Polish aurochs, a size of 170-185 cm in bulls and 165 cm in cows is given (Kysely 2008). This means that the cow might have been 170-175 cm tall at the withers in life.

So the height of European aurochs cows found so far varied between 137 cm (minimum) and 175 cm (maximum) in life, while the bulls varied from 160 cm to 200 cm or more. Van Vuure gives an average size as it follows: 160-180 cm in bulls and 150 cm for cows (van Vuure 2002, 2005). While this is probably an accurate average, this range however does not represent the variation found in the European aurochs well enough. Also I don't know if this is an estimation for living specimen or skeletons. 

While both sexes varied considerably in size, the bulls of the respective populations were always at least one or two decimetres larger than the cows. This is a dimorphism similar to what we see in other wild bovines. It would be interesting to know how large the variation was within a population - if large aurochs cows reached the size of small aurochs bulls or if bulls were always and under any circumstances larger than cows. 

What is worth noticing is that both sexes apparently varied by 40 cm. This is considerable. A reason for that might be that not all individuals found were fully grown. A strong regional gradient is not detectable since the smallest Danish bulls apparently reached 154 cm (skeleton), while the largest Danish skeleton that is mounted measures 190 cm according to various sources from the internet (the Preljerup bull). So the aurochs probably was simply diverse in size. 

Literature 

Boessneck, 1956: Funde des Ures, Bos primigenius Bojanus 1827, aus den alluvialen Schichten Bayerns. 

Kysely, 2008: Aurochs and potential crossbreeding with domestic cattle from the Eneolithic period. A metric analysis of bones from the archeological site of Kutna Hora-Denemark (Czech Republic). 

Frisch, 2010: Der Auerochs - das europäische Rind. 

Schibler et al. 2014: Incorporation of aurochs into a cattle herd in Neolithic Europe: single event or breeding? 

Van Vuure 2005: Retracing the aurochs - history, morphology and ecology of an extinct wild ox. 

Van Vuure 2002: History, morphology and ecology of the aurochs.