B.p. namadicus: bone material + new artworks

I already did a couple of posts on the Indian aurochs, Bos primigenius namadicus, the most comprehensive and up-to-date being this one. At the time of writing that post, the only picture of original material of this enigmatic subspecies I knew was a drawing of one skull. Thanks to a Carnivora Forum member I finally came across photo material of a few specimen. The two upper photos show bulls for certain, I am not sure about the last one.

The skull material

The crania show some very interesting morphological differences to the European subspecies, B. p. primigenius. First of all, the skulls are definitely narrower than European skulls (the upper one might still be within the variation range, though) and most zebus tend to have a very slender face as well. The horns of the known specimen are, as given in the literature, wide-ranging and considerably longer in proportion than the average for European skulls (which had, though, regional and chronological variation).  Considering that many zebuine or zebuine-influenced breeds tend to have large to very large horns, this might be a basal trait – although the huge horns of, for example, Watussi and similar breeds have certainly been enhanced by domestication.

There is also a more precise drawing of the Lydekker skull available on the web, which also shows it in lateral view. At least this skull seems to have the same 60° horn orientation as in the average European aurochs.

New Indian aurochs art

Seeing these photos of original bone material of the Indian aurochs has inspired me to do some new life illustration of this interesting subclade. As explained in the post linked above, there are a few traits that can be said with certainty, some that can be inferred by parsimony and some traits displayed by zebuine cattle might actually be wildtype traits of the Indian aurochs.

Directly proven traits:

- smaller body size, perhaps between 150-160cm for bulls

- proportionally longer, wide-ranging horns

Traits inferred by parsimony:

- a more slanted pelvis than in taurine cattle

- basic aurochs and wild cattle morphology (long legs, athletic body)

- E⁺ base colour

Zebuine traits that might in fact be wildtype traits:

- longer dewlap than in the European aurochs (functional purpose: thermoregulation)

- zebuine colour modifiers

Putting everything together, here is the result:

The head and horn shape was drawn to match the skull material. I tried to give the face a kind of zebuine appearance. The body shape is the classic aurochs body shape (I do not assume any differences in proportions, hump size or other morphological traits as long there is evidence for). As for the colour, here is were intuition comes into play. Many zebus show white areas between the forelegs, on the dewlap and also the underbelly, which is said to be caused by a “zebuine tipping gene” (it is not specified whether it is an extra locus or just an allele) and also displayed by other bovine species. I like to illustrate my namadicus with this trait. Also, zebus tend to have another form of colour saddle, different from taurine cattle. It is not a true saddle that covers the upper middle part of the torso, but the sides and often merges fluently into the “zebu tipping area”. Many zebuine bulls show this trait, and it might just be a consequence of reduced sexual dimorphism as in taurine bulls, but for this drawing I assumed it to be a wildtype trait. It is pure speculation, but intuitively I think it is not an improbable colouration for a tropical bovine, which tend to be more colourful than boreal ones.

I also did not give it any curly forelocks. Forelocks are well-proven for the European subspecies and the wide majority of taurine bulls and also cows have them, yet no zebuine cattle show curly forelocks. Tropical bovines tend to have skin flaps and long dewlaps for display, while those in temperate climates tend to have hairy ornamentation for thermoregulatory reasons, thus I think it is plausible that Indian aurochs did not posses forelocks but an elongated dewlap instead. In previous posts I ruled out that the zebuine hump has any function, and therefore did not assume its presence for Indian aurochs. However, a Carnivora Forum member pointed out it might have had a display function in the wildtype, just as the enlarged processus spinosi have in Gaur and Banteng. This is very speculative, however, and probably only prehistoric art could provide a clue.

Being motivated by my new Indian aurochs bull portrait, I could not hesitate to do a table of bulls of all three aurochs subspecies along with their domestic descendants.

As there is only evidence for black aurochs bulls in Europe, I gave the primigenius bull a solid black back. However, for the African aurochs, there is evidence from at least two artworks that at least some bulls of this subspecies had a colour saddle (see here). So the colouration of the African bull is not as speculative as that of the Indian bull. It might as well be possible that all three geographical variants had a solid black colour like the European one. As there are no morphological differences between the African and European aurochs noted in the literature, the African and the European aurochs are actually the same drawing, only the colouration is different. The subspecies that sticks out is the Indian one, which is not surprising considering that the lineages of taurine cattle and zebuine cattle, and thus B.p. primigenius and B.p. namadicus, separated 1,7-2 million years ago[1], which is considerably longer than between Przewalski’s and domestic horses, for example. Here is a close-up for the Indian aurochs alone:

I think the drawing does look plausible for the wildtype of a bull like this one down below.

Something interesting that I noticed is that the size difference between all five bovines is not that huge, especially not between the wildtypes and their domestic derivatives. I drew them to the same scale. For the European aurochs, I chose a size of 170cm at the withers, for the African 160cm and for the Indian aurochs 150cm (which is, by the way, the lower size limit for European mainland bulls). The taurine bull has a height of 140cm, the zebu about 135cm. But the size difference does not appear that large. I think the reason for that is that withers height is not the most reliable measure for this comparison, as it is dependent on the size of the hump i.e. the length of the processus spinosi, actually. In very derived taurine bulls and most zebu the height of the spine does not surpass that of the shoulder blade, thus a domestic bull with a withers height of 150cm would have a larger body than an aurochs of the same withers height, especially considering that they are more elongated in build. So what is actually better comparable is the height of the shoulder blade. The question is, how much higher is the actual height of the shoulder blade of aurochs compared to cattle? Is it due to scaling or is the size difference between aurochs and cattle not that large in the end? The best way to evaluate that would be to compare a skeleton of a grown aurochs bull to that of a domestic bull in real next to each other. But considering that heavy bulls of domestic breeds can easily exceed 1000kg living weight while estimations for aurochs bulls are about 700kg  (by Cis van Vuure, I have reasons to believe they might have been actually 100-200kg heavier, but more on that in an upcoming post) it might not be that improbable. Surely, some aurochs individuals truly were huge by cattle standards as there are skulls of European aurochs with a length of more than 90cm.

In any way, I did an animated GIF of a the European aurochs and the taurine bull at the same withers height – it is obvious that the taurine bull has a way larger body due to the low processus spinosi and the elongated trunk. Even the head would have the same size. A taurine bull with a shoulder height of 170cm would have a weight of about 1700-1800kg, which is twice as much as what is estimated for an aurochs bull of that size.

“Breeding-back” with zebus, once again

In all my previous posts on the Indian aurochs, I introduced the idea of “breeding-back” with zebus. India is full of zebu landraces that are not well-known elsewhere but would be suitable for such a project as they have a slender, squarely-built body with long legs and long snouts. These include Kenkatha, Malvi, Ponwar, Haryana, Khilari or the large-horned Gudjerat. Such indigeneous zebus could be crossed with Watussi for the horn size and curvature and miniature zebus for the aurochs-like colour and dichromatism. Both Watussi and miniature zebu have taurine introgression, but as we know from “breeding-back” with taurine cattle, it is impossible to keep the taurus and indicus lineage 100% separated and it is the contributed traits that count, not pedigree. While the morphology and external appearance of the European aurochs is well-known and breeding with its descendants can approach most of its traits rather well, the life appearance of the Indian subspecies is far less well-known and zebus seem to be a bit more removed from their ancestor than taurine cattle. At least, there are no truly overall primitive zebuine breeds. However, breeding with the zebuine cattle listed above can produce a population that resembles namadicus in horn shape and size, proportions, skull shape and probably also colour. Most interesting would be to release them in a reserve and let them live for themselves for a number of generations. Heck cattle in Oostvaardersplassen underwent morphological changes after a mere 30 years of natural reproduction (see here, here or here) and it is likely that these zebu would experience something similar. These changes would be functional and evolutionary advantageous as they are the result of natural selection. Therefore, it would be interesting what happens to the shoulder- and neck region of the cattle. In Oostvaardersplassen, Heck cattle developed a tendency to have a stronger shoulder region including the typical hump of wild bovines with elongated shoulder spines that support larger neck- and shoulder muscles which are needed during combat. In zebuine bulls, the neck muscles seem somewhat weaker which might be a consequence of the fleshy zebuine hump which is caused by a hypertrophied M. rhomboideus. Thus, a bull with a zebuine hump might be in disadvantage compared to such with a wild cattle-like shoulder morphology. If, after a couple of generations, the zebuine hump would indeed disappear and they would develop a wild cattle-like hump like Heck cattle at OVP, it would be a strong hint that the fleshy zebuine hump is an artefact of domestication and was not present in namadicus as it is not functional. If, however, zebus do indeed use it for display, head-to-head combat might play a lesser role in their social life than in taurine cattle, and it might remain. This can only be demonstrated by executing such a zebu dedomestication experiment.

Other posts on the Indian aurochs: 

- The Indian aurochs III (2017)

- Life illustration of the Indian aurochs (2015)

- The Indian aurochs: breeding-back with zebus? (2013, outdated) 

Literature

1 Hiendleder, Lewalski, Janke: Complete mitochondrial genomes of Bos taurus and Bos indicus provide new insights into intraspecies variation, taxonomy and domestication.2008.

Further, for the description of namadicus and africanus in the Literature:

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