The whole aurochs issue is centred almost entirely around the European subspecies, B. p. primigenius because it is the best-documented subspecies and survived the longest. The Indian aurochs, the wild ancestor of the zebu, was the first one to disappear and is very enigmatic. There are only few skeletal remains (a number of crania, some postcranial material), no artistic depictions have been claimed to show this population nor are there written accounts. What we can infer from the fossil-subfossil record is that namadicus was smaller than primigenius (van Vuure 2005 mentions that some crania were slightly smaller than those female Pleistocene primigenius). But proportionally, its horns were larger and more wide-ranging (the only graphic representation of namadicus material I was able to find is that skull).
Therefore, much of its appearance is unknown. In a post I did two years ago, I tried to deduce some additional traits based on the scarce info we have and what seems credible looking at living zebu and relatives. I consider the presence of a fleshy zebuine hump unlikely for the wild-type (see the 2013 article). From all the traits I hypothesized back then, here is a short summary plus some new thoughts regarding colouration:
- proportions and body shape similar to primigenius, including a hump caused by high processus spinosi (no reason to think otherwise)
- a posteriorly slightly down-turned pelvis
- The dewlap might have been longer than in the European subspecies (although probably not as extreme as in living zebu). Bovids in tropical climate often have fleshy appendages for display and thermoregulation.
- Since all un-mixed zebu breeds (as far as I know) have a typical E+//E+ colour, namadicus probably had a colour very similar to the European aurochs: black or very dark bulls, much lighter coloured bulls, muzzle ring in both sexes and a dorsal stripe at least in bulls. Many zebu have a diluted colour similar to podolian cattle, but there are some that have a colour not different from the European aurochs (see here). Zebus usually have the “zebu tipping gene” that causes a lightly coloured area between the forelegs that may also extend to the belly and dewlap. This might either be a mutation that happened right at the base of domestication, or it was a trait possessed by namadicus already. In my new reconstruction, I illustrate the latter option. The question if the hair between the horns had a colour different from the rest of the head is as unclear as it is in the European subspecies (it probably did not have the curlyforelocks of the European subspecies, since no zebu and no tropical bovine has them). Some zebu show white rings around the eye, even males, as on this photo by Markus Bühler. Perhaps this was the case in namadicus too, especially because Banteng also show it. I consider it likely that cows would have it, but perhaps not all bulls. Many aurochs-like-coloured zebu bulls have a saddle, and this kind of saddle is different from that of taurine bulls: interestingly, their saddle is not centred on the back of the trunk, but on the sides. This might be a mutation as well, but for this illustration I speculated it is a primitive state.
All in all we get a more colourful aurochs for India. That is not unlikely, because bovids of tropical climates are often rather colourful.
Before I present my current reconstruction, I want to share some comments on my old one (by the way; I have to admit that I am seemingly a kind of pioneer in illustrating B.p. namadicus, I did my first reconstruction in 2011 and I saw only one further illustration that might be namadicus). The old one has some anatomical flaws (position of the hump in the bull), and artistic ones (perspective of the horns). I drew the waist a bit too slender for my taste now, and the deep ribcage plus the high, straight hump makes it look too gaur-ish too me today. Regarding the cow, I would still agree with it more or less nowadays, but I will illustrate a female Indian aurochs another day. So for now, I drew only a bull. Colour and stature were inspired by this miniature zebu bull.
It might surprise that all its living descendants look so different. But I would say that is because there are simply no truly primitive zebus left. Imagine all primitive taurine breeds would vanish and the only breeds we would have left are such like Angus, Holstein, Galloway and Belgian blue. I cannot say why there are no primitive zebus left. It is possible that a genetic bottleneck was responsible, or strong artificial selection or both.
As I outlined in my 2013 post, a breeding-back project for B. primigenius namadicus could be done. But only a rather minimalistic one, since we have no precise idea of the wild-type and all descendants are rather derived. On the other hand, there are zebus which have a rather aurochs-like colouration, such as those linked in this post, and there are breeds like Some Gudzerat/Kankrej and other zebu that have proportions and horn dimensions that are good and also useful horns (in our minimalist expectations). Watussi have horn sizes that would help compensating the small horn sizes of other zebu, and some of them also have a curvature that is not bad (being Sanga cattle, they are mixed with taurine cattle; but the reverse also is often the case so why not tolerating it). Looking at site for primitive, useful zebu in India and south-east Asia might also show up some helpful results.
I think it would be possible to breed a population of zebu that have the right colouration and horn size, and a horn curve plus proportions that is tolerable. I might illustrate this idea too some day. They would still show some of the “weird” zebu traits (overlong dewlap, large hanging ears, fleshy hump). Nature would on a long-term sight further refine traits such as body shape, neck- and shoulder muscles (zebu hump vs. spine-caused hump), dewlap, horn orientation (there are no zebu with forwards-pointing horns that I know of) and so on. Since we have no certain clue on colouration, a certain amount of variation should be permitted (after all, even the grey dilution factors could be a primitive state).
I am going to illustrate the African subspecies, B. p. africanus, soon.