History of Earth the late Paleozoic. The Mesozoic ("middle life") era lasted from 251 Ma to Ma. It is subdivided into the Triassic, Jurassic, and Cretaceous periods. The era began with the Permian–Triassic extinction event, the most severe extinction event in the fossil record; 95% of the species on Earth died out. It ended with the Cretaceous–Paleogene extinction event that wiped out the dinosaurs.. The Cenozoic ("new life") era began at Ma, and is subdivided into the Paleogene, Neogene, and Quaternary periods. These three periods are further split into seven sub-divisions, with the Paleogene composed of The Paleocene, Eocene, and Oligocene, the Neogene
Gulf Keystone Petroleum is notably one of the largest Super Giant oilfields discovered in the last 50 years. Shaikan was declared a commercial discovery on August 1, 2012 following a five-well appraisal program. Initially independent estimates place the gross oil-in-place (OIP) volume at 13.7 billion barrels (P50) potentially making it one of the largest oilfields discovered in Iraqi Kurdistan. The oilfield covers an area of some , and comprises a series of limestone reservoirs stacked upon each other. These reservoirs encompass a very long period of geological time, from the Cretaceous which ended some 65 million years ago to the Triassic, which began