05026 - Beautiful Pyritized 1.79 Inch Phylloceras Lower Cretaceous Ammonites Hexanchus Yale University

Yale University

The complicated sedimentarian architecture of the layers where most large vertebrates are found makes the excavation methodology a real challenge

as large as or slightly bigger than Tyrannosaurus and possibly slightly larger than Giganotosaurus

Still nowadays the Dromaeosauridae family has not been officially described in the dinosaur assemblage of the Upper Cretaceous of this sector

05026 - Beautiful Pyritized 1.79 Inch Phylloceras Lower Cretaceous Ammonites Hexanchus Yale UniversitySpecimen of extreme quality. 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.