A horned dinosaur of unprecedented proportions has recently been given the "horns up" of approval by Guinness World Records, recognized as the largest Triceratops skeleton

Nicknamed "Big John", the super-sized specimen of Triceratops horridus – the most familiar of the ceratopsian dinosaurs – dates to the Late Cretaceous, circa 100–66 million years ago. 

Big John’s mounted skeleton, which is about 60% complete, measures approximately 7.15 m (23 ft 5 in) long from snout to tail tip – almost twice the length of a white rhino. It stands 2.7 m (8 ft 10 in) tall measured at the hips. 

The reconstructed skull, which is about 75% complete, is 2 m (6 ft 6 in) wide and has a basal skull length – i.e., the distance between the tip of the snout and where the head attaches to the body – of 1.55 m (5 ft 1 in). 

Each of Big John's brow horns measures 1.1 m (3 ft 7 in), longer than a field hockey stick!

All three of Big John’s horns – for which Tri-ceratops takes its name – are in fairly good condition, with the formidable two brow horns each measuring 1.1 m (3 ft 7 in). 

According to scientists who analysed the remains at the University of Bologna in Italy, Big John’s skull is 5–10% larger than that of any other Triceratops officially reported to date. 

Professor Philip Currie, a world-renowned palaeontologist at the University of Alberta, Canada, and a dinosaur consultant for Guinness World Records who was not involved with Big John’s discovery or restoration, commented: "Over the years I have looked at lots of Triceratops fossils, but this is unquestionably the largest Triceratops skull I have ever seen."

Big John with his GWR certificate, presented by natural history and fossil expert Iacopo Briano in Paris

"In fact, it positively dwarfs the skulls of all the other ceratopsians that we find in Alberta and that I normally work with, which makes it all the more impressive!," Currie continued.

Originating from the USA, the skeleton was reassembled by palaeontological preparation company Zoic in Trieste, Italy, with assistance from natural history and fossil sales expert Iacopo Briano. 

Big John has been on display in the Marais district of Paris, France, since September and has already been drawing a lot of attention. Briano said: “We need to clean windows at the gallery several times every day – kids literally smear against the glass with a big ‘Wooooooow’!”

Big John on display in Trieste, Italy, where the skeleton was reconstructed

"The best reactions for me are the ones of specialists from museums and potential buyers who are flying from literally all over the world. Everyone is slightly shocked at first – the term ‘speechless’ would be most appropriate." - Iacopo Briano, natural history and fossil sales expert

It took a little less than eight months of skilled work of the Zoic team to bring Big John back to life, starting from the bones still encased in plaster jackets. 

The biggest challenge was the fact that Triceratops’ postcranial anatomy (the skeleton apart from the skull) is still not completely known and casts of missing bones were hard to realize. 

Luckily, Zoic already worked on two other major Triceratops specimens: Cliff, at the Boston Museum of Science, and its "cousin" at the Gwacheon National Science Museum in South Korea.


Big John is due to be sold by Drouot auction house in Paris on 21 October and is expected to realize big bucks, with an estimate starting at €1.2 m ($1.4 m; £1 m). To date, the most expensive dinosaur bones sold at auction were those of a T. rex skeleton – nicknamed “Stan” – which sold for £24.57 m ($31.84 m; €27.08 m) at Christie’s in London, UK, on 6 Oct 2020. 

Big John was discovered in the Hell Creek Formation of South Dakota, USA, in 2014 by geologist Walter Stein, and was then carefully excavated over the next two years. Hell Creek is one of the richest hotspots for Late Cretaceous dinosaur remains in the world, with several other record-breaking prehistoric finds made here:

Scotty, one of the largest T. rex specimens ever unearthed

  • Most complete Tyrannosaurus rex  – a 4-m-tall (13-ft), 12.5-m-long (41-ft) 90%-complete skeleton christened “Sue”, after Sue Hendrickson who found the bones in 1990. 
  • Largest known T. rex specimen – a record also held by Sue for many years. But in 2019, a Canadian contender for this title, who goes by “Scotty”, stomped onto the scene, vying for the crown. Because the two T. rexes are so similarly sized, it was decided that they should share the record. 
  • Largest carnivore coprolite – a prodigious fossilized poop measuring 67.5 cm (2 ft 2.25 in) long. Its size, contents (bone remnants) and location indicate it most likely came from a T. rex. Owned by coprolite collector George Frandsen (USA) – curator of the Poozeum, the world's largest collection of coprolites – he named the mega-poo “Barnum” in honour of Barnum Brown who uncovered the first described T. rex in 1902.  

In the new Guinness World Records 2022 book, the Triceratops is one of six record-breaking dinosaurs you can virtually resurrect via the medium of augmented reality (AR). Learn how you can bring dinosaurs back to life.