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The first stem-group teleosts appeared during the Triassic (teleosts are by far the most diverse group of fish today). [53] Predatory actinopterygians such as saurichthyids and birgeriids, some of which grew over 1.2 m (3.9 ft) in length, appeared in the Early Triassic and became widespread and successful during the period as a whole. [56]
The Mesozoic Era [3] is the era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Periods.It is characterized by the dominance of archosaurian reptiles such as the dinosaurs, and of gymnosperms such as cycads, ginkgoaceae and araucarian conifers; a hot greenhouse climate; and the tectonic break-up of Pangaea.
This work assessed the geologic history of the currently defined eons and eras of the pre-Cambrian, [note 2] and the proposals in the "Geological Time Scale" books 2004, [74] 2012, [5] and 2020. [75] Their recommend revisions [ 4 ] of the pre-Cryogenian geologic time scale were (changes from the current scale [v2023/09] are italicised):
The discovery, made public Wednesday, includes well-preserved footprints of reptiles and amphibians that scientists say date back 280 million years to a geologic period known as the Permian period.
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 ...
The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between 251.9 Ma and 246.7 Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which is a unit in chronostratigraphy. The Early Triassic is the oldest epoch of the Mesozoic Era.
Footprints dating back 120 million years show where dinosaurs were able to cross between land that's now part of two different continents. Matching dinosaur footprints found more than 3,700 miles ...
Recognizable humans emerged at most 2 million years ago, a vanishingly small period on the geological scale. The earliest undisputed evidence of life on Earth dates at least from 3.5 billion years ago, [7] [8] [9] during the Eoarchean Era, after a geological crust started to solidify following the earlier molten Hadean eon.