I own an aurochs horn now: what it tells us

Recently I purchased an aurochs horn from most likely or at least the 15^th century. It is not only the only one in private hands known, but also the largest aurochs horn sheath known and beautifully preserved. It is from a private collection and was inherited by Daniel Vanackere who gave me the opportunity to purchase it. His family owned the horn for centuries in Rotterdam. Very, very big thanks to Daniel Vanackere to give me the opportunity to acquire the horn! 

 

Here it is:

It measures 134 cm at the outer bow, 13,5 cm at the anteroposterior diametre, 11 cm in dorsoventral diametre and 41 cm in circumference at the base. The beauty of this horn is that it is almost completely unmodified, just one or two centimetres at the base seem to have been cut off and there is an attachment for what might have been a belt that was attached onto the horn in the 15^th century. Most putative aurochs horn sheaths that we see are sanded down and polished, and the tip is often cut off (see here for example). My horn is completely the way it was on the living bull, except for a slight discolouration on the surface as it is 500 years old. But one can still recognize where the blackish tip starts and where the yellowish part of the horn was. 

 

I think it is highly likely that it is from a pure, mature male aurochs. I think so because of the curvature (yes, the tip curves outwards but read on), the dorsoventrally compressed horn base (a trait very expressed in Pleistocene aurochs, less so in Holocene aurochs and not in most domestic cattle), the size, the thick base and the very slim tip (a contrast less expressed in domestic cattle) and the keel on the ventral side of the horn (a keel on the horn is a very ancient trait in aurochs, most common in the Indian aurochs and some zebu). 

Concerning the curvature, we should consider that of most aurochs horns only the bony cores are preserved while sheaths that definitely are from pure aurochs are very rare. I wanted to know what the bony core of the horn would have looked like and so I made a “cast” of partly plaster, wire and tissue paper, and this is the result: 

As we can see, the bony core has a perfect aurochs shape and with 70 cm it also fits in dimensions. It is just that the horn tip does not follow the curvature of the bony core, but makes a turn and curves outwards-forwards. I have been puzzling about that. I assumed that maybe there was much more variability in the shape of the horn sheath than the bony cores suggest. My first thought to that assumption was: but the depictions of aurochs all show inwards-curving horns. But then thought further and it came to my mind that there are actually quite a few aurochs depictions with lyre-shaped horns. For example, this one from a chalcography from 1596, showing an aurochs hunt in Bavaria: 

Scan from Walter Frisch's Der Auerochs, original photo by Museum Karlsruhe

Or the famous depiction in Siegismund von Herberstein’s book showing his aurochs taxidermy:

It is usually assumed that the horns in this depiction were simply invented by the artist and that they were lacking in the taxidermy. However, it shows the wavy surface of my horn and the shape is compatible as well. 

 

And then there would be the depiction of the African aurochs in Beierkuhnlein 2015 [1]. 

 

In the past, I did not put much emphasis on the depicted lyre-shape of the horns, assuming that the artists did not pay much attention to the actual horn shape or that they invented the horns, or did not see life aurochs in real et cetera. But looking at my horn, I see that differently now. I have no idea how common such an outwards-curving tip in the aurochs was, it could have been 1%, 10%, 80% of bulls, everything is possible. 

 

How does the horn fit with other preserved aurochs horn sheaths? First of all, it is its incredible size that sticks out. Medieval aurochs horns usually are not nearly as large as those of earlier ages, particularly the Pleistocene. But this one is. Also, late aurochs had a quite round horn base, much more like domestic cattle than earlier aurochs. But mine has a dorsoventrally compressed horn base, as a Pleistocene aurochs would. Also it has the keel on the ventral side which I haven’t seen in any other putative aurochs horn sheath yet. So morphologically, my horn fits much older aurochs better than other aurochs horn sheaths from the medieval times onwards. How can that be interpreted? I see several possibilities: a) the sample size (some dozens of sheaths) is too small to correctly determine the variability of very late aurochs horns, b) my horn is much older than the 15^th century c) the other putative aurochs horn sheaths are from aurochs that were hybrids with domestic cattle and my horn is one of the very few, or perhaps the only one, preserved that is from an aurochs free or almost free of domestic influence. 

I tend to favour explanation c. The sample size is not that small, I have seen at least 20 sheaths so far. And all of them are rather small by aurochs standards, except for my horn. Explanation b would require that the horn somehow survived that well preserved a very long time, which makes it unlikely that it was found in turf, permafrost or soil as it would now be discoloured which it is not. The only scenario I can think of is that the horn has been in human hands since, for example, the Roman times and got passed on by generation to generation. But I don’t know if that scenario is plausible. 

But there is considerable reason to assume that many very late aurochs populations were actually hybrids with domestic cattle. Hybridization in both directions between cattle and aurochs has been found on the Iberian Peninsula [2]. A study examined 7 putative aurochs horn sheaths genetically, and it was found that 3 of them have domestic cattle mitochondria, including the horn of the last bull from Jaktorow from 1620 (which is only 46 cm long and very weakly curved, with the base and the tip being almost equally thick) [3]. That the other ones have the P haplotype does not rule out introgression from cattle as some cattle have that haplotype and it does not tell us anything about the nuclear genome. 

 

I assume the horn belonged to a bull because of the thick horn base and the size of the sheath. It could be that it was an old mature bull, since horns continue to grow until death and the tip is very long (it makes up 48% of the length of the horn). Old bulls are solitary and do not fight for mating rights anymore, so they could effort to have that long and thin horn tips. I estimate the bull was 15 to 20 years old at time of death. I would like to know the story of that bull, and the precise locality where it died.  

This is what the set of horns might have looked like on the living animal: 

This of course makes me wonder how large the bull was. I tried to calculate the withers height of the bull using photos of two very large-horned specimens, the Etival and the Sassenberg bull. I calculated the relative size of the horn diametre at the base to the withers height and multiplicated it with the diametre of my horn. The result was 190 cm. Considering that I used skeletons as a reference that would have been surrounded by soft tissue in the living animal, the bull might have been between 195 and 200 cm tall at the withers in life. 

 

 

I am sure some of you will be familiar with the curvature of the horn. Many Maronesa cows, some Sayaguesa cows and also many Tudanca (in this breed also the bulls) have a horn curvature that is very similar to that one. I used to think that these outwards-forwards curving horn tips are a domestic mutation, but my horn changed my perspective on that. It seems possible that this is part of the variation of the aurochs, and has been preserved in breeds such as Maronesa and Tudanca. 

 

I think this underlines the preciousness of Maronesa. It is the only breed still in existence that I know of that has a colour that 100% matches that of the European aurochs, with a well-marked sexual dichromatism. It is also one of the very few breeds that has strongly inwards-curving horns and it seems that the corkscrew-like curvature seen in many cows is part of the natural variability of the aurochs. A Maronesa-Tudanca lineage could maybe reproduce the curvature of my horn precisely. 

 

Literature 

 

[1] Beierkuhnlein, 2015: Bos primigenius in ancient Egyptian art. 

[2] Günther et al.: The genomic legacy of Human management and sex-biased aurochs hybridization in Iberian cattle. 2023 (preprint). 

[3] Bro-Jorgensen et al., 2018: Ancient DANN analysis of Scandinavian medieval drinking horns and the horn of the last aurochs bull.