Scientists and designers unveiled on Thursday (April 2) a handbag made with collagen derived from Tyrannosaurus rex fossils from the U.S. in a unique creation intended to demonstrate the value of laboratory-grown leather.

The teal-colored bag will be displayed on a rock in a cage under a replica of a T. rex at Amsterdam's Art Zoo museum until May 11 after which it will be auctioned, with a reported starting price of more than half a million dollars.

Scientists behind the initiative said the material was developed using ancient protein fragments extracted from dinosaur remains that were inserted into an unidentified animal's cell to produce collagen that was turned into leather.

Some scientists outside the project have expressed skepticism about the term "T. rex leather," saying material from other animals would be needed.

Dutch vertebrate paleontologist Melanie During, of the Vrije Universiteit Amsterdam, said collagen can persist in dinosaur bones only as fragmented traces that cannot be used to recreate T. rex skin or leather.

Thomas R. Holtz Jr., a paleontologist at the University of Maryland, similarly said any collagen identified in T. rex fossils comes from inside bone, not skin, and that even perfectly matching proteins would lack the larger‑scale fiber organization that gives animal leather its distinctive properties.

Production: Piroschka van de Wouw, Yiming Woo, A. Lennon/Reuters