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Pangaea or Pangea (/ p æ n ˈ dʒ iː ə / pan-JEE-ə) [1] was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. [2] It assembled from the earlier continental units of Gondwana , Euramerica and Siberia during the Carboniferous approximately 335 million years ago, and began to break apart about 200 million years ...
Laurasiatheria (/ l ɔː r ˌ eɪ ʒ ə ˈ θ ɪər i ə,-θ ɛr i ə /; "Laurasian beasts") is a superorder of placental mammals that groups together true insectivores (eulipotyphlans), bats (chiropterans), carnivorans, pangolins (), even-toed ungulates (artiodactyls), odd-toed ungulates (perissodactyls), and all their extinct relatives.
More than 99 percent of all species that ever lived (over five billion) [1] are estimated to be extinct. [ 2 ] [ 3 ] Estimates on the number of Earth's current species range from 10 million to 14 million, [ 4 ] with about 1.2 million or 14% documented, the rest not yet described . [ 5 ]
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 gymnosperms such as cycads, ginkgoaceae and araucarian conifers, and of archosaurian reptiles such as the dinosaurs; a hot greenhouse climate; and the tectonic break-up of Pangaea.
The largest inlet from Panthalassa, the superocean that surrounded Pangaea, was called the Tethys Ocean, and as this inlet cut deeper into the supercontinent, much of Europe was flooded. By the Cretaceous , from 145 to 66 million years ago, the continents were beginning to approach their present shapes, but not their present positions, and ...
Mammals and birds that survived the extinction fed on insects, larvae, worms, and snails, which in turn fed on dead plant and animal matter. Scientists theorise that these organisms survived the collapse of plant-based food chains because they fed on detritus. [18] [15] [19] In stream communities, few groups of animals became extinct. Stream ...
Figure 1:In mammals, the quadrate and articular bones are small and part of the middle ear; the lower jaw consists only of dentary bone.. While living mammal species can be identified by the presence of milk-producing mammary glands in the females, other features are required when classifying fossils, because mammary glands and other soft-tissue features are not visible in fossils.
[38] [39] Modern crocodilians can live as scavengers and survive for months without food, and their young are small, grow slowly, and feed largely on invertebrates and dead organisms for their first few years. These characteristics have been linked to crocodilian survival at the end of the Cretaceous.