Comparing skeletons with skeletons

I always thought that it would be best to not compare living cattle with aurochs skeletons or with accurate aurochs reconstructions because it actually is a) imprecise and b) comparing apples with oranges because the skeleton of living animals is surrounded by soft tissue attached to it, and therefore making our comparisons less correct. Of course I am talking in reference to proportions, muscle size, and other morphologic features such as hump size et cetera. The best and most precise method for this is to compare osteologic material of the aurochs to that of the breeds of interest. The problem: there are no articulated, prepared skeletons of those. Therefore I had the idea to get an impression how the skeleton roughly looks like by deducing it from photos of living cattle. All you need is a pen, piece of paper and basic knowledge on the anatomy of these animals. It’s basically the reverse of a life restoration. For example, the M. trapezius tells you approximately where the shoulder blade ends, in less-muscular cattle you can even see the outline of this bone through the skin. Same with the pelvis. The elbow, knee and knuckles show where the limb elements end. If you know a bit about the soft tissue on a cattle’s head, you can deduce how the skull inside looks. Eye, ears and horns are a useful reference points. I also used qualitative cattle skeleton illustrations as an aid, see here and here.

I used photos of 10 cattle breeds, five of which I did both bull and cow. I chose either individuals representative for their breed or those which look very aurochs-like from “outside” and I wanted to check if they do so on osteologic basis. Mind that these drawings are very schematized and I only cared about what is relevant for these comparisons, so please no complains on irrelevant details like vertebra or rib count/shape. I messed up some of the skulls, but I plan to do an extra skull series anyway.

For the metric evaluations, I took the trunk length as reference again. Trunk length is defined as the horizontal distance from the anteriormost part of the scapula to the posteriormost part of the pelvis. Shoulder height is defined as vertical distance between the ground and the top of the shoulder blade. In living animals, we tend to define the shoulder height as distance from the ground to the withers, but these comparisons are worthless because they are influenced by the hump size, which is actually a different factor. I define the hump as the vertical distance between the top of the shoulder blade and the top of the shoulder spines. Again, in reference to the trunk length. However, this is not totally precise, because it makes a difference if only a few of these spines have that length or the complete anterior half of the trunk spine. But you have the drawings of the skeletons from which you can see that.

So that we know what we are comparing, I did those measurements with two representative complete aurochs specimen, the Braunschweig bull and the Sassenberg cow (of course I had to correct the articulation of the bones before, since virtually all skeletons on display are mounted incorrectly):

Braunschweig:

Trunk/leg length: 1:0,81

Hump size: 1:0,09

Head size: 1:0,35

Sassenberg:

Trunk/leg length: 1:0,95

Hump size: 1:0,05

Head size: 1:0,36

Braunvieh (bull)

 

Trunk/leg length: 1:0,82

Hump size: virtually 0

Head size: 1:0,3

Original photo

Chianina (bull)

 

Trunk/leg length: 1:0,8

Hump size: 1:0,05

Head size: 1:0,25

Original photo

Heck (bull)

Trunk/leg length: 1:0,81

Hump size: virtually 0

Head size: 1: 0,26

Original photo

Heck (cow)

Trunk/leg length: 1:0,84

Hump size: 1:0,016

Head size: 1:0,28

Original photo

Lidia (bull)

Trunk/leg length: 1:1

Hump size: 1:0,08

Head size: 1: 0,34

Original photo

Lidia (cow)

Trunk/leg length: 1:0,95

Hump size: 0,045

Head size: 1:0,29

Original photo

Maremmana (bull)

Trunk/leg length: 1:0,87

Hump size: 0,05

Head size: 0,35

Original photo

Maremmana (cow)

Trunk/leg length: 1:0,94

Hump size: 1:0,04

Head size: 0,3

Original photo

Maronesa (bull)

Trunk/leg length: 1:0,83

Hump size: 0,045

Head size: 0,24

Original photo

Maronesa (cow)

Trunk/leg length: 0,95

Hump size: 1:0,043

Head size: 1:0,28

Original photo

Pajuna (bull)

Trunk/leg length: 1: 0,82

Hump size: 1:0,04

Head size: 1:0,20

Original photo

Podolica (bull)

Trunk/leg length: 1:0,92

Hump size: 1:0,048

Head size: 1:0,36

Original photo

Sayaguesa (bull)

Trunk/leg length: 1:0,89

Hump size: 1:0,023

Head size: 1:0,3

Original photo

Sayaguesa (cow)

Trunk/leg length: 1:0,89

Hump size: 1:0,06

Head size: 1:0,31

Original photo

Taurus (bull)

Trunk/leg length: 1:0,82

Hump size: 1:0,034

Head size: 1:0,29

Original photo

I actually wanted to include the perfectly-proportionated and perfectly-shaped Heck bull Oostvaardersplassen bull as well, but the resolution is too small. Bear in mind that these measurements provide only rough relations, as this method is surely prone to imprecisions and is never as effective as working with real skeletons. But I think the overall impression is sufficiently accurate. Looking at the proportions of the skeletons, the Heck bull and the Braunvieh bull are the least aurochs-like. The trunk is long, head small and hump non-existent, as you see in living animals. The Heck cow has a shorter trunk, but there are more longish ones of course, and the hump is absent. Surprisingly, the Chianina bull has the longest trunk. This is probably the reason why first-generation Heck x Chianina bulls usually were still long and massive. The Pajuna bull has a long trunk, but apart from that, it’s skeleton is pretty good. The head is large and longish, the hump is acceptable. The Taurus bull is well-proportionated as well, except that the head could be larger. The hump is good, but could be larger as well.

All the other skeletons are awesome. Like I expected, the skeletons of both the Lidia cow and bull fit the aurochs in virtually all respects – proportions, hump size, skull size and length (bull, the cow seems to be subadult). Also their silhouettes resemble a wild animal like the aurochs most closely. The skeletons of both the Maremmana (belonging to Tauros Project, by the way), the Sayaguesa cow and the Podolica are very aurochs-like as well. The hump size of that Sayaguesa cow (Tauros Project again) is impressive. The hump of the Sayaguesa bull (father of the Taurus bull) seems a bit too small. The skeleton of the Maronesa cow is superb, as much as her life appearance. The Maronesa bull has a very aurochs-like skeleton as well, if the trunk was larger it would be as aurochs-like as the Lidia bull, apart from the head.

My conclusion is that the osteometric features of the postcranial skeletons of the most primitive cattle are very similar to the aurochs. According to an old German reference, the aurochs’ bones are said to be more robust than those of domestic cattle, probably partly due to the more strongly developed muscle attachment areas and because they have to resist the stresses caused moving at high speed and fighting against conspecifics and predators. I guess that this comparison was done with very derived “usual” cattle, but I think that the primitive breeds might be somewhere in-between, because they are still less muscular and less tight-bodied as the aurochs probably was – with the possible exception of the very muscular Lidia. The fact that the body of most primitive cattle is not as athletic as that of wild animals is not all too problematic in my opinion. The phenotypic changes in some of the cattle at OVP has shown that the body shape gets more athletic due to living in the wild, caused by phenotypic and probably genetic changes, even when the founding population are un-athletic Heck cattle. The skeleton of many of the OVP cattle still has to change in order to match the aurochs, and this will take yet more decades. Considering that Tauros Project works with well-proportioned animals of which some have very aurochs-like skeletons as you see above, they might surpass the current OVP Heck cattle regarding body shape and proportions right from the beginning when the Tauros cattle are opposed to natural selection. But for that I think they have to get rid of the Highland cattle and short-legged Limia individuals.