Bones found in 2014 in what is now South Dakota described as ‘miracle of nature and work of art’

In its time, approximately 66m years ago, the triceratops, with its massive collared skull and three attacking horns, was one of the most dangerous and daunting of dinosaurs.

Now the remains of one of the giants of the Cretaceous period, a herbivore despite its fearsome appearance, have gone on display in Paris before they are auctioned next month.

Big John, as the dinosaur has been named, has a skull and bony collar measuring 2.62 metres long, 2 metres wide and weighing more than 700kg, two large horns measuring more than a metre, and 200 other assorted bones that have been painstakingly pieced together.

He lived in Laramidia, an island continent that stretched from what is now Alaska to Mexico, and died in an ancient flood plain now known as the Hell Creek geological formation in South Dakota. As the plain is composed of sediment with no biological activity, Big John was mostly fossilised and preserved.

The bones were discovered in May 2014 and excavation was completed more than a year later. They were reassembled in Italy at the Zoic workshop, specialists in the restoration of prehistoric skeletons.

A laceration on the collar suggests the dinosaur was injured in combat with another triceratops, probably in defence of territory or a mate.

“Big John, over 60% complete and with a 75% complete skull, is both a miracle of nature and work of art,” said a spokesperson for the auctioneers, Giquelo.

Iacopo Briano, a palaeontologist who oversaw the reconstitution of Big John, said the skeleton was 5-10% bigger than any other triceratops found up to now.

“It’s a masterpiece,” Briano told FranceInter radio. “There are quite a few triceratops skulls around in the world, but very few of them almost complete.”

Alexandre Giquello, of the auctioneers, said such an enormous skeleton would be of interest to only about a dozen buyers around the world.

“Each auction, we see new profiles arrive. We have seen owners of unusual places who want to invest to attract customers. There are also people who are passionate about science and palaeontology. They are often quite young, coming from new technologies; they are in fact the Jurassic Park generation: they have seen the movies and have been immersed in this Hollywood mythology,” Giquello said.

Experts say the craze for dinosaur skeletons remains high and is pushing up prices, to the frustration of museums and research centres often unable to raise the funds.

Last October, a rare allosaurus skeleton, one of the oldest dinosaurs, considered to be the “grandfather” of the dreaded T-rex, was sold in Paris to an anonymous bidder for a little over €3m, twice the estimate.

Big John, who measures 8 metres long, is expected to fetch up to €1.5m when he goes under the hammer at Paris’s Drouot auction house on 21 October as part of the annual Naturalia sale. He can be seen between 16 September and 15 October at 13 rue des Archives in the city’s Marais district.