Not one, not two, but three rare dinosaur fossils stormed Christie’s on December 12.

The auction house sold the fossils as part of a sale titled Jurassic Icons: Allosaurus and Stegosaurus that featured a pair of allosaurus fossils—one juvenile and one adult—as well as the skeleton of a stegosaurus, all three of them aged between 145 and 157 million years old.

The dinosaur remains were sold for a total of £12.4 million ($15.7 million), exceeding their asking prices. The duo of allosaurus skeletons sold for a total of £8.1 million ($10.2 million), surpassing their collective estimate of £5 million–£8 million ($6.3 million–$10.1 million); while the stegosaurus fetched £4.2 million ($5.3 million), when it was expected to bring in £3 million–£5 million ($3.2 million–$6.3 million).

“We are thrilled with the results,” James Hyslop, Christie’s London head of science and natural history, said in a statement, “which reflect the lasting allure of these remarkable specimens and their unparalleled insight into the ancient world.”

The skull of the adult allosaurus. Photo: Christie’s Images Ltd.

All three skeletons on sale were excavated, reconstructed, and sold by Interprospekt, a Swiss-German company that organizes excavations, exhibitions, and educational programs connected to natural history and geology.

The allosaurus lived from 155 to 144 million years ago, during the Late Jurassic Period. An apex predator competing with the tyrannosaurus rex, the average adult specimen stood over 15 feet all, and possessed a bite force of more than 3,500 Newtons, comparable to the modern-day wolf. The fact that the auction’s juvenile skeleton was found near its adult counterpart suggests that allosauruses were social creatures, rather than lone hunters.

The stegosaurus skeleton. Photo: Christie’s Images Ltd.

Contrary to what its imposing back-plates might suggest, the stegosaurus was a herbivore, subsisting on a diet of mosses, ferns, horsetails, conifers, and fruit, which it ground down with small stones deposited inside its stomach. As with modern-day herbivores and insectivores, like the porcupine, its back plates weren’t used for hunting so much as protection, scaring off actual predators looking for an easy meal.

Although Christie’s dinosaurs brought in a considerable sum of money, they don’t hold a candle to Apex, the stegosaurus skeleton which Sotheby’s sold for a whopping $44 million back in June (its buyer, hedge fund billionaire Ken Griffith, has loaned the specimen to New York’s American Museum of Natural History). Apex, the first stegosaurus to come to auction, beat the record previously held by Stan, a complete tyrannosaurus fossil that Christie’s fetched $31.8 million in 2020 (the nation of Abu Dhabi was later revealed as the buyer).