The skeleton of a Heck bull

When comparing living cattle to the aurochs, there is the danger of comparing apples with bananas when examining skeletons versus living animals. We do not know the aurochs' life appearance for sure, we only know the skeletons for sure. Thus, a fruitful approach could be comparing the skeletons of aurochs-like cattle to that of aurochs. I have seen some Heck bull skulls previously, but never a complete skeleton. Recently, I found the photo of a Heck bull skeleton mounted in France. It is from the publication Remaques sur l'osteometrie de l'aurochs-reconstitue: interet pour la selection de la race (code 30) en vue de se rapprocher du Bos primigenius by Claude Guintard and Quentin Blond. 

© Claude Guintard

Guintard has done a number of publications on Heck cattle, comparing it to the aurochs. The paper in particular looks at this skeleton plus a skull of the Heck bull Axis from the Wörth/Steinberg lineage. 

Go here for a skeleton of an aurochs bull. As you see, the trunk of the Heck bull is longer. If the trunk was shorter, the legs would be longer in relation to the overall size and would fit the aurochs better. The Heck bull has a hump, but smaller as in the aurochs. Also, the skull is shorter but not much compared to that particular specimen. There are aurochs bulls with much longer snouts (such as the Sassenberg bull), and also comparably short-snouted individuals (such as the Torsac dirac bull skeleton) which are comparable to average domestic cattle in skull shape. 

Besides the differences in proportions, there are also differences in the horn shape. The horns of the Heck bull would have to curve inwards more strongly in order to fit the aurochs. The dimensions of the horns are within the European aurochs' range of variation. 

References 

Claude Guintard, Quentin Blond: Remaques sur l'osteometrie de l'aurochs-reconstitue: interet pour la selection de la race (code 30) en vue de se rapprocher du Bos primigenius. 2018.