The oldest ancestors of the domestic ox discovered

The most ancient ancestors of the domestic ox were discovered in the Indus Valley and in the Fertile Crescent in Mesopotamia: they are remains of aurochs (Bos primigenius) dating back to about 10 thousand years ago. The research published in the journal “Nature” and conducted by Trinity College Dublin and the University of Copenhagen, involved Luca Pandolfi, paleontologist from the Department of Earth Sciences of the University of Pisa, who has long been dealing with evolution and the extinction of large continental mammals also in relation to climate change.

The domesticated aurochs were animals quite similar to the wild ones, but a little smaller, especially with less developed horns indicating greater tameness. In fact, Julius Caesar in “De Bello Gallico” (6-28) describes the wild aurochs as an animal slightly smaller in size than the elephant, fast and of a particularly aggressive nature. From the fossil remains it emerges that wild aurochs could reach a height of just under two meters, weigh 1000 kg and have horns more than one meter long. Their presence dominated the faunas of Eurasia and North Africa starting around 650 thousand years ago, and then underwent a sharp decline from the end of the Pleistocene, around 11 thousand years ago, until its extinction in the modern age. The last known specimen was shot down in Poland in 1627.

The study in “Nature” analyzed “for the first time this species to understand its evolutionary and genetic history through fossil remains found in various sites in Eurasia, including Italy, and North Africa”, explains Luca Pandolfi.

Ancient DNA samples were extracted from the finds, which include complete skeletons and well-preserved skulls. Their analysis therefore made it possible to identify four distinct ancestral populations that responded differently to climate change and interaction with humans. European aurochs, in particular, suffered a drastic decline in both population and genetic diversity during the last ice age, about 20,000 years ago. The decrease in temperatures in fact reduced their habitat, pushing them towards the Italian and Iberian Peninsulas from which they subsequently recolonized the whole of Europe.

“During the Quaternary, an era that goes from 2 and a half million years ago to today, the aurochs was the protagonist of the ecosystems of the past, contracting and expanding its habitat in relation to the climatic vicissitudes that characterized this period of time – concludes Pandolfi – the bones of these majestic animals tell paleontologists the story of the success, adaptation and decline of a species whose extinction we ourselves contributed to and reveal the complexity and fragility of the relationships that bind living organisms to the climate of the our Planet”.

(by Paolo Martini)