The Cretaceous is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin creta, "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation Kreide.
The impact of a meteorite or comet is today widely accepted as the main reason for the Cretaceous–Paleogene extinction event.
Drawing of fossil jaws of Mosasaurus hoffmanni, from the Maastrichtian of Dutch Limburg, by Dutch geologist Pieter Harting (1866)
Scipionyx, a theropod dinosaur from the Early Cretaceous of Italy
Facsimile of a fossil of Archaefructus from the Yixian Formation, China
The Mesozoic Era is the second-to-last era of Earth's geological history, lasting from about 252 to 66 million years ago, comprising the Triassic, Jurassic and Cretaceous Periods. It is characterized by the dominance of gymnosperms and of archosaurian reptiles, such as the dinosaurs; a hot greenhouse climate; and the tectonic break-up of Pangaea. The Mesozoic is the middle of the three eras since complex life evolved: the Paleozoic, the Mesozoic, and the Cenozoic.
Plateosaurus (a prosauropod)
Sericipterus
Stegosaurus
Tylosaurus (a mosasaur) hunting Xiphactinus
