GeologyRocks

The final period of the Mesozoic. This period spans 145.5-65.5Ma. The end of the Cretaceous was marked by the KT (now properly called the KP) extinction event, which saw the demise of the dinosaurs as well as several other groups such as ammonites.

It contains the following eras:

• Berriasian 145.5-140Ma
• Valanginian 140-136Ma
• Hauterivian 136-130Ma
• Barremian 130-125Ma
• Aptian 125-112Ma
• Albian 112-99Ma
• Cenomanian 99-93Ma
• Turonian 93-89Ma
• Coniacian 89-85Ma
• Santonian 85-83Ma
• Campanian 83-70Ma
• Maastrichtian 70-65.5Ma

The Berriasian to the Albian is the Lower Cretaceous. The Cenomanian to the Maastrichtian is the Upper Cretaceous.