| Williams Fork Formation | |
|---|---|
| Stratigraphic range: Campanian (Edmontonian) ~ | |
| Type | Geological formation |
| Unit of | Mesaverde Group |
| Lithology | |
| Primary | Mudstone |
| Other | Sandstone |
| Location | |
| Coordinates | 40°00′N108°48′W / 40.0°N 108.8°W |
| Approximate paleocoordinates | 47°30′N80°18′W / 47.5°N 80.3°W |
| Region | Colorado |
| Country | United States |
The Williams Fork Formation is a Campanian to Maastrichtian (Edmontonian) geologic formation of the Mesaverde Group in Colorado. Dinosaur remains are among the fossils that have been recovered from the formation, most notably Pentaceratops sternbergii ,. [1] Other fossils found in the formation are the ammonite Lewyites , tyrannosaurids, dromaeosaurids, troodontids, nodosaurids, ankylosaurids, hadrosaurids, hybodonts, neosuchian crocodylomorphs, and the mammals Glasbius and Meniscoessus collomensis . [2] [3]