Yolanda Schicker-Siber gingerly fastens a pointy claw bone with a thin metal wire, finishing a giant Tyrannosaurus Rex skeleton before next month’s rare auction in Switzerland. She’s the curator of Aathal Dinosaur Museum in Switzerland and is helping complete perhaps the world’s most extensive construction kit — reassembling a 67-million-year-old T-Rex dubbed Trinity.
The dinosaur, which weighed at least eight tons when it was alive, is currently being sold for around $15 million to $20 million, according to Sotheby’s, the New York-based auction house that holds the sale (opens in new tab). A partial skull has already been removed, and the rest will be ready for an online public bid this December.
“Tyrannosaurus rex is a critical animal in our field, and this specimen shows it,” said Steven Nesbitt, a paleontologist at the American Museum of Natural History in New York. He and his colleagues have studied several different T. rex fossils, but this is the most complete one yet.
In addition, it has two puncture marks on the skull and neck that scientists believe may be evidence of fights with other T. rex, possibly even from another species.
The Tyrannosaurus Rex was a giant predator with three horns, a long neck, and a ferocious bite. It also had a heart-shaped lung and a rib cage that was big enough for its entire body to fit into.
Researchers estimate that a staggering 2.5 billion T. rex lived during their lifespan, but only 32 have survived as fossils. Nevertheless, they have been recovered in various geological formations, including the Hell Creek Formation in Montana and the Cretaceous-Tertiary-Cretaceous boundary in North America.
A recent study by Charles Marshall and his colleagues at the University of California, Berkeley, estimated that T. rex reached sexual maturity between 14 and 17 years of age, weighing in at about 250 to 300 pounds. And they calculated that it would have needed about 28 years to reach full size and die, based on its mass, growth rate, and population density.
It is hard to know how many T. rex existed because it’s difficult to tell where they died and whether they survived as fossils. But Marshall and his colleagues came up with an estimation by combining existing research on T. rex with a theory known as Damuth’s law, which suggests that larger animals tend to have higher populations than smaller ones and, therefore, a more comprehensive range of individual fossils.
According to Marshall, if the scientists had not done this, they might have missed out on a treasured T. rex fossil, and the planet would have lost an essential species.
Moreover, the estimate is a powerful tool to help scientists better understand the preservation rates of T. rex fossils. It helps them calculate how rare it is to find a specimen.
But it’s important to remember that T. rex is just one of the hundreds of fossilized dinosaurs; not all are well-preserved or have been identified as adults. So the fact that the team managed to come up with this estimate is awe-inspiring, given how rare it is to get a good T. rex fossil in the first place and how little we know about these ancient beasts.