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Tertiary (/ ˈ t ɜːr. ʃ ə. r i, ˈ t ɜː r. ʃ i ˌ ɛr. i / TUR-shə-ree, TUR-shee-err-ee) [1] is an obsolete term for the geologic period from 66 million to 2.6 million years ago. The period began with the extinction of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start of the Cenozoic Era, and extended to the beginning of the Quaternary glaciation at ...
Tertiary crust is the most differentiated type of crust and so has a composition vastly different to that of the bulk Earth. [16] The tertiary crust contains over 20% of the abundance of incompatible elements , which are elements with a size or charge that prevent them from being included in mineral structure. [ 16 ]
Many modern mammal groups begin to appear: first glyptodonts, ground sloths, canids, peccaries, and the first eagles and hawks. Diversity in toothed and baleen whales. 33 Ma Evolution of the thylacinid marsupials . 30 Ma First balanids and eucalypts, extinction of embrithopod and brontothere mammals, earliest pigs and cats. 28 Ma
An early stem-primate, Plesiadapis, still had claws and eyes on the side of the head, making it faster on the ground than in the trees, but it began to spend long times on lower branches, feeding on fruits and leaves. The Plesiadapiformes very likely contain the ancestor species of all primates. [24]
c. 850 Ma - Start of the Neoproterozoic oxygenation event, a second major increase in atmospheric and oceanic oxygen concentration on Earth. [ 23 ] c. 830 Ma – Rift develops on Rodinia between continental masses of Australia, eastern Antarctica, India, Congo and Kalahari on one side and Laurentia, Baltica, Amazonia, West African and Rio de la ...
These divisions were used to describe both the time during which the rocks were laid down, and the collection of rocks themselves (i.e., it was correct to say Tertiary rocks, and Tertiary Period). Only the Quaternary division is retained in the modern geologic time scale, while the Tertiary division was in use until the early 21st century.
World renowned Austrian neurologist Sigmund Freud introduces his theory on psychosexual development, which asserts that there is an immature clitoral orgasm and a mature vaginal orgasm. He states that the clitoris is the site for pre-pubescent orgasms but upon reaching puberty, healthy women should begin having vaginal orgasms instead.
The Laramide orogeny, which began in the Late Cretaceous, continued to uplift the Rocky Mountains; it ended at the end of the Paleocene. [53] Because of this and a drop in sea levels resulting from tectonic activity, the Western Interior Seaway , which had divided the continent of North America for much of the Cretaceous, had receded.