The world's biggest Triceratops skeleton has sold in Paris for $7.7m to a U.S. collector.
The dinosaur remains had a ticket price of $1.7m at Thursday's auction but went for more than four times that estimate.
Nicknamed Big John, the skeleton was found in South Dakota, U.S. in 2014 and is 66 million years old. The find has been described by paleontologists as a miracle of nature and a work of art.
The skeleton is more than 60 percent complete, with a 75 percent complete skull.
What is a triceratops?
- The triceratops is one of the most recognizable dinosaurs because of the three horns on its head (its name means "three-horned face").
- It also had an enormous distinctive bony collar.
- Despite its ferocious appearance, the animal was a herbivore.
- They lived more than 60 million years ago.
- Big John was found bearing notable scars believed to have been inflicted by another of its kind, possibly in a battle over territory or a mate.
- The skeleton is 8 meters long and its skull makes up a quarter of the animal’s length.
- The huge skull weighs 700kg.
Big John's remains were discovered in a single fossil layer within a relatively small quarry in privately owned land at Mud Butte Ranch, South Dakota, in 2014.
The excavation of Big John was completed more than a year later.
The bones were reassembled in Italy at the Zoic workshop, by specialists in the restoration of prehistoric skeletons.
The area where the skeleton was found forms part of the Hell Creek Formation, a division of rocks in North America dating to the end of the Cretaceous Period some 65.5 million years ago.
It was deposited as coastal-plain sediments during the withdrawal of the shallow Cretaceous seas that covered much of the interior of western North America.
The area has been a rich hunting ground for paleontologists – along with other triceratops skeletons, the fossilized remains of tyrannosaurus (possibly the most famous of all dinosaurs), ankylosaurus (a small, armor-plated dinosaur) and pachycephalosaurus (an unusual two-legged dinosaur with a bony dome on top of its head) have been found in the region.
In the Hell Creek Formation, most of the known quarries produce highly disarticulated, or separated, specimens, whereas Big John's elements were still partially articulated at the time of discovery.