PARIS , -- Thursday's sale of the world's largest triceratops skull, "Big John", to a Paris private collector was worth 6.6 million euros ($7.7million).

In 2014, the enormous skeleton was discovered in South Dakota. It is estimated that it is more than 66 million years old. Three horns on its head are what make the triceratops famous.

Big John is named after the owner who found it. It is the Guinness World Records' largest documented skeleton of an triceratops. The dinosaur was killed in an ancient flood plain that ran from Alaska to Mexico. This allowed for the preservation of its skeleton in the mud.

The length of the skeleton is 7.15m (23 feet), and it stands 2.7m (8 feet) high at its hips. With two large horns measuring over 1.1 meters (3.6 feet) in length, the skull makes up more than a third of its total length.

Before commission, the Drouot auctionhouse hammer price was 5.5 millions euros.

Alexandre Giquello, an auctioneer, said that it was a European record.

Big John's skull is over 75% complete and his skeleton more than 60%, making him unique.

Iacopo Brino, a paleontology expert said that Big John's overall quality was worth the price. "For a herbivore and for a triceratops. He said that it was an incredible record.

A Tyrannosaurus Rex skeleton sold for almost $32 Million in a New York auction last year. It was the most expensive dinosaur ever to be sold.

Big John was sold privately to an American buyer who asked to remain anonymous.

Djuan Rivers, the representative of the buyer, stated that "it's being purchased by an American collector... absolutely delighted with the idea to be able to bring something like this to my personal use."

"The history and duration of this project is incredible. Rivers said that being able to preserve this natural heritage is an honor and a privilege.