Pycnodonte newberryi (Stanton) is a species in the Pycnodonte genus of extinct oysters, marine bivalve mollusks in the family Gryphaeidae. It lived from the Cretaceous period, 90 to 130 million years old. P. newberryi fossils generally exist in large layers or beds. In the state of Utah, in the USA, in the Capital Reef National Park area, this layer of fossils ranges up to ten feet thick. The layer is present in the lower Tununk section of the Mancos Shale Fraction, just above the Dakota Sandstone and below the Blue Gate Shale layer. In the Hanksville, Utah area the Pycnodonte newberryi oyster bed is exposed over a large area. Studies are currently being conducted to determine if there is more than one species in these beds.