What dinosaur has 500 teeth? This prehistoric jaw was one-of-a-kind. This dinosaur’s skull was light as air but its mouth was packed with power—and a unique ability to quickly grow teeth.

A new dinosaur species, Enigmacursor mollyborthwickae, has been identified from a partial skeleton found in Moffat County, Colorado, researchers said.

The 150-million-year-old specimen is valued at up to $6 million by Sotheby’s. Some paleontologists worry this auction and earlier ones are driving fossil market speculators.