160,000,000 BP to 140,000,000 BP
145,000,000 BP to 140,000,000 BP: time of the Berriasian Age of the Cretacious Period.
145,000,000 BP to 66,000,000 BP: Cretaceous Period is divided into two Ages: the Valanginian Age and the Berriasian Age. During this time placental mammals appear. It is also the time of the beginnings of the Laramide and Sevier orogenies of Rocky Mountains of North America. Atmospheric co2 was close to present day levels.
140 Mya to 130 Mya: This is the Valanginan Age of the Cretaceous Period.