Following is a timeline of events based on the fossil record of Earth:
a map of the earth at the end of the Cretaceous
Cretaceous Period[]
- 65.5 mya: an asteroid the size of Mt. Everest just barely misses the Earth; had this asteroid struck the Earth, nearly 70% of all life on Earth would have been snuffed out in an instant
Paleogene Period[]
- 55.8 mya: the Paleocene-Eocene Thermal Maximum occurs, resulting in the greatest and fastest increase in global temperature of these entire Cenozoic Era; rain forests are spread across the globe, forcing most animals to shrink in size
- c. 55 mya: pachycephalosaurs (dome-headed dinosaurs) die out completely due to the thermal maximum, and ceratopsids and birds suffer greatly; ceratopsids never recover, but birds return en masse as enenornithes, apsaraviformes, paleognathes, and fowl; tyrannosaurs fall into decline and shrink down to their former Jurassic Period sizes
- c. 55 - 50 mya: India collides with Asia, resulting in a faunal interchange: rahonavid dromaeosaurs invade Laurasia, mostly living in trees; abelisaurs spread out from India and into the main continent
a map of the earth between the Paleocene and Eocene Epochs