150 million years old, the specimen was excavated in Utah and turned green when mineralization replaced parts of the original bone with iron-rich compounds during fossilization.
The fossil ranks among North America’s most complete sauropod reconstructions, giving the museum a standout centerpiece in its Dinosaur Hall.
More than 35 million specimens are held by the museum, the largest natural history museum in the western United States, linking Gnatalie to a broader record of Southern California’s prehistoric past.