The Pen Formation is a Campanian-age geologic unit in the western United States.
Sharks are well known from the Pen Formation. [1]
Other fishes include Xiphactinus, [1] the ray Ptychotrygon, [1] and gar. [1] The nodosaurid ankylosaurs Acantholipan and CPC 273 have also been found in the Pen Formation. [2]
The Pen Formation is a Campanian-age geologic unit in the western United States.
Sharks are well known from the Pen Formation. [1]
Other fishes include Xiphactinus, [1] the ray Ptychotrygon, [1] and gar. [1] The nodosaurid ankylosaurs Acantholipan and CPC 273 have also been found in the Pen Formation. [2]