07531 - Top Quality Pyritized 0.98 Inch Unidentified Lower Cretaceous Ammonites Dinosaur Age Mammals Onchopristis is a genus of

Onchopristis is a genus of extinct giant sawfish that lived in the Lower Cretaceous to Upper Cretaceous in North Africa and New Zealand

They come from the famous sites of the Judith River Formation in Montana (Campanian stage

This is a complete vertebra of this very rare giant fish of filter feeder diet

K/T Boundary Latest Cretaceous Bidart France Dinosaur Extinction Stratigraphical Level

Anetoceras elegantulum

07531 - Top Quality Pyritized 0.98 Inch Unidentified Lower Cretaceous Ammonites Dinosaur Age Mammals Onchopristis is a genus ofSpecimen of extreme quality. Unidentified species. His suture lines are wonderfully well detailed. It is naturally pyritized. It has undergone a taphonomic process of permineralization in Iron Sulfide (Pyrite). Permineralization is a process of fossilization in which mineral deposits form internal casts of organisms.