A giant puzzle that the curator of the Aathal Dinosaur Museum in Zurich meticulously reconstructed over two days with other experts. The bones of the T-Rex, an animal that lived 67 million years ago, traveled to Zurich from Arizona, USA, in nine giant crates.

Called Trinity, the skeleton, about 3.9 meters high and 11.6 meters long, is placed on a red carpet, under crystal chandeliers, in the middle of a Zurich concert hall where it will be on display before its sale on April 18.

According to the auction house Koller, it is estimated at between six and eight million Swiss francs (similar amounts in euros). This is a "fairly low" estimate, warned the natural history expert of the house Koller, Christian Link, while we are witnessing a real craze of buyers for this type of relics.

Trinity is actually an assembly of bones from three different T-Rex found between 2008 and 2013 in formations in Montana and Wyoming, in the northwest of the United States, according to the sales catalog.

It was at these sites that two other important T-Rex skeletons were discovered and auctioned: in 2000, Stan was sold for $31.8 million, shredding the previous record set by Sue, sold in 1997 for $8.4 million.

Installation of a dinosaur skeleton, "Trinity", before its auction, in Zurich, Switzerland on March 28, 2023 © ARND WIEGMANN / AFP

Last year, the auction house Christie's had to withdraw a few days before the sale in Hong Kong another skeleton of T-Rex - also from Montana - because of doubts about the authenticity of parts of the fossil.

Very, very old

Reconstituting Trinity was no easy task, Schicker-Siber told AFP. "The bones are very, very old. They are 67 million years old. So they are fragile, they have cracks," she explains.

Aart Walen, who has 30 years of experience assembling dinosaur skeletons, agrees. "We haven't broken anything yet," he says proudly, as he and his colleagues work on two large ischia, located near the pelvic area from which the eggs emerge.

With a budgie perched on his shoulder, Mr. Walen fills in the cracks in the bones, using what looks like dental tools and modeling clay. It was important that the repairs were visible, he said, pointing to the dark areas where the cracks were.

"We have to see where the repairs have been made. There are stories of fakes circulating. We don't want that," he said.

Yolanda Schicker-Siber of the Aathal Dinosaur Museum in Zurich participates in the installation of a T-Rex skeleton to be auctioned, in Zurich, Switzerland on March 28, 2023 © ARND WIEGMANN / AFP

It also shows that the sound is different depending on whether it hits the bone or the plastic pieces that helped complete the skeleton.

Artwork

Just over half of the skeletal bone material comes from the three tyrannosaurus specimens, which is higher than the 50% rate needed for experts to consider such a skeleton to be of high quality.

The Koller house wanted to be transparent about the origin of the bones. "Hence the name Trinity. We make no secret of the fact that this specimen came from three different excavation sites," Link said.

Still, for paleontologist Thomas Holtz, Trinity "is not really +a specimen+ but rather an art installation". According to him it is "misleading" and "inappropriate (...) to combine real bones from different individuals to create a single skeleton."

In an email to AFP, he more generally criticized the auctions of important dinosaur skeletons and other fossils, which have brought in tens of millions of dollars.

Installation of a T-Rex skeleton for an auction, in Zurich, Switzerland on March 28, 2023 © ARND WIEGMANN / AFP

These sales, for example, risk depriving the scientific community of access to these specimens when they are purchased by a private collector, experts warn.

An argument rejected by Mr. Link, for whom 95% of known T-Rex are in museums.

The Swiss dinosaur museum Aathal, which Schicker-Siber runs with her father near Zurich, unfortunately cannot afford to acquire Trinity. "But if someone buys it and doesn't know where to put it, we have a museum -- with enough room -- for a T-Rex."

© 2023 AFP