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. 

How many times did the primigenius spiral evolve?

The horn shape of the aurochs can be compared to a spiral, which is called the "primigenius spiral" in the literature (see van Vuure 2005). It is universal to all aurochs specimen known, what probably had functional reasons: this horn shape is simply practical in intraspecific fights, as they enable to push and pull the opponent. 

Looking at other bovine species, it becomes obvious that the primigenius spiral is found also in species other than Bos primigenius. Wild yaks have horns identical to that of the aurochs in both dimensions and curvature (see here or here). It is also found in male koupreys (see here). Occasionally, the primigenius spiral also appears in wisent (see here).

Now the question is: did the primigenius spiral evolve independently in these species, or was it already found in their common ancestor? 

In order to resolve that question, we have to look at the phylogeny of the Bos-Bison clade. 

+--- Bos primigenius (aurochs, including taurine and zebuine cattle) 

 `-+---+--- Bos sauveli (kouprey)

    |       `+--- Bos javanicus (banteng)

    |          `--- Bos gaurus (gaur)

     `+--- Poephagus mutus (yak)

        `---- Bison  

This phylogeny is based on mitochondrial data from three studies [1,2,3]. The wisent, as it is a special case, is not included in my cladogram. 

If the primigenius spiral evolved independently in the three species aurochs, yak and kouprey, it must have evolved three times according to the cladogram. If it goes back to a common ancestor, which would be the common ancestor of the Bos-Bison clade, it must have been lost two times again, once in the bison clade and once in the banteng-gaur clade which possess more crescent-shaped horns. But did banteng and gaur really lose the primigenius spiral? It depends on the angle you are looking at the horns. When looking from above, it becomes obvious that even banteng still have the primigenius spiral (see the horns of this cow), the horns are just more upright. And considering that this shape still can occur in wisent, it might indeed be possible that the primigenius spiral is basal for all members of the Bos-Bison clade. 

The primigenius spiral is even found in Leptobos, a possible ancestor of the Bos-Bison clade, at least in the species Leptobos stenometopon (see here). 

Putting everything together it is not unlikely that the basic horn shape of the aurochs, the primigenius spiral, was basal to all members of the Bos-Bison clade. 

[1] Hassanin et al.: Has the kouprey (Bos sauveli Urbain, 1937) been domesticated in Cambodia? 2006.

[2] Verkaar et al.: Maternal and Paternal lineages in cross-breeding bovine species. Has the wisent a hybrid origin? 2004.

[3] Wang et al.: Incomplete lineage sorting rather than hybridization explains the inconsistent phylogeny of the wisent. 2018. 

The lost Berlin skull, the Sassenberg cow and the Vig bull

I am constantly trying to reconstruct as many aurochs specimen as possible to get an impression of the variation in the European subspecies, B. p. primigenius. Recently I did another three artworks, as usual by reconstructing directly over photos of the actual skeletal material, to be as precise as possible. 

The lost skull from Berlin 

There is a very large aurochs skull on display at the Natural History Museum of Berlin. But the museum also had another skull which is now lost. It was part of a complete skeleton which was on display at the museum and may be now in the collection. Here you can see the photo of the skeleton which my reconstruction is based on. 

All rights reserved. 

The horns seem to be oriented in an angle larger than 60° to the skull (which is the average according to van Vuure 2005). The horns are also not that strongly inwards-curving, at least not the bony cores. The keratinous sheath adds about 10% to the length of the horn in my reconstruction, which may even be conservative. 

The horns resemble those of some Watussi and some Heck cattle of the Steinberg/Wörth lineage, at least from this angle. 

The Sassenberg cow 

The Sassenberg cow specimen was the subject of the previous post. Now I also did a reconstruction of the head in profile view. 

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The skull of aurochs is usually more elongated than in most domestic cattle, but this is more apparent in bulls than in cows. The skull shape of cows of some landraces, for example Sayaguesa, might be similar to that of the Sassenberg cow. Note that my reconstruction of the cow is not supposed to be completely black, but only neck and face as in many wildtype coloured cows. 

The Vig bull 

I reconstructed the Vig bull already several times, here is my most recent reconstruction. Using a photo by Markus Bühler I did another one recently: 

© Markus Bühler

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I think the mount is anatomically correct enough to be used for a reconstruction, I just slightly altered the position of the hind legs. The horns of the Vig bull are comparably upright, which is apparent in this view (I estimate 85° relative to the skull). 

The Sassenberg cow

The Sassenberg cow specimen is the only mounted skeleton that is certainly a cow of Bos primigenius primigenius that I know of (the Cambridge specimen is dubious to me, it's not 100% certain that it is a cow), the other definite cow skeletons that I know belong to B. p. suxianensis (see here). It was found in Sassenberg, Germany, in the 19th century. 

Skeletal material of aurochs cows is much rarer on display than that of the bulls, probably because they are "less impressive". I assume it is unlikely that less female skeletons have been found, most of them are probably in collections. 

Due to copyright issues I cannot post the photos of the skeleton that I have, but my skeletal reconstruction down below was done by tracking out a photo of the skeleton and therefore should give an accurate impression. 

Skeleton, muscle reconstruction and life reconstruction of the Sassenberg cow specimen © All rights reserved, please do not use without permission. 

The skeleton shows that cows had a shorter trunk than bull skeletons, which is congruent with the description of live aurochs in Anton Schneeberger's letter to Gesner (1602), who wrote that cows are shorter than the bulls. It also shows that also the cows had humps in the shoulder region (not only the bulls), indicated by the elongated processus spinosi in the shoulder region.  Humps in cows is rare in domestic cattle, it is found in draft breeds like Sayaguesa or Maronesa, but to the largest extent in Lidia. My life reconstruction bears some resemblance to what a cross of Lidia, Maronesa and Sayaguesa would look like, what fits my proposal of a breeding project with those three breeds. 

Here a Sayaguesa cow for comparison (the cow Dona-Urraca from the Lippeaue): 

The reconstruction above shows the cow in its summer coat, but I also did one of the individual in a longer coat during fall: 

The Sassenberg cow with a shagger coat during fall. Please do not use without permission. 

It is not known how long the winter coat of the aurochs was. Schneeberger wrote that the aurochs was covered with longer hair than domestic cattle. Whether this was generally the case, or referred to the coat during winter and fall, is unknown.