A fossilised skeleton unearthed in Spain may extend both the range and timespan of the animal family that today contains just giraffes and okapis, according to a report in the open access journal PLOS ONE.

The Giraffidae family was once a diverse group spread throughout Eurasia and Africa. More than 30 fossilised species have been described, but today the only survivors are confined to Sub-Saharan Africa.

This new giraffid species has been named Decennatherium rex, by a team led by María Ríos from Madrid’s National Museum of Natural History.

Its fossilised bones were found during mining operations at a site near Madrid and are thought to date from the late Miocene, about 20 million to five million years ago. The skeleton is unusually complete, revealing new anatomical and evolutionary data.

The researchers say this is the first time that modern quantitative methods have been applied to “this understudied and morphologically bizarre mammal”.

The new species is estimated to have weighed about 1000 kilograms and would have been smaller than modern-day giraffes.

The researchers believe the Decennatherium genus may have been the earliest example of a group of now-extinct giraffids, known as sivatheres and samotheres, whose defining feature was four horn-like skull protuberances, called ossicones.

This the first time a distant giraffe ancestor has been found in the Iberian peninsula, significantly extending the ancient range of the family.