In April, Polish fashion brand Enfin Levé dropped a bombshell straight from the late cretaceous period: a handbag they claim is made of “lab-grown T-rex leather.”

The startling announcement made headlines throughout the luxury design world, which was quick to balk at the nearly $600,000 starting price at a coming auction in Paris. In the scientific community, however, experts are skeptical of the entire premise, with some wondering whether the material truly counts as coming from the iconic Tyrannosaurus rex at all.

According to German publication DW News, the debate stems from the definition of “T-rex leather.” Back in 2005, paleontologists uncovered what they believed to be soft tissue connected to the 68-million-year-old bones of a T–rex in Montana — a biological discovery previously believed to be impossible.

That bit of tissue has caused a ton of fuss, with some researchers arguing the tissue was really a clump of bacteria colonizing the fossil instead of genuine dinosaur flesh, DW explained.

The authenticity of the sample has major implications for the Enfin Levé bag, the designers of which used data from the tissue sample to produce the “leather.”

Further complicating things is the presence of chicken protein — which was fused with the T–Rex’s supposed protein sequence to create the leather material for the $600,000 bag. As postdoctoral researcher and fossilized protein expert at the University of Turin told DW, that means the resulting material doesn’t really qualify as dinosaur.

“What they have done is create synthetic collagen using an AI model trained on a variety of different species, mainly chickens,” Dekker explained. “A very interesting development in itself, but it is not a dinosaur. In fact, it’s more chicken than anything else.”

Even if the bag isn’t made of genuine Tyrannosaurus hide, though, the whole situation offers a fascinating glimpse at the state of lab-grown leather, which offers a cruelty-free alternative to an industry otherwise fueled by factory farms.

More on lab creations: Lab-Grown Brains Growing More Powerful