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Prehistoric Scratchpad

Mammals which give live birth to their young without a protective shell.

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  • Phylum Chordata (Chordates) - Animals with a backbone or closely related to one.
    • Class Mammalia
      • Order Multituberculata (Multituberculates) - A group of successful rodent-like mammals that with origins in the Triassic and lasted until after the fall of the dinosaurs until they were out-competed by rodents and other mammals. The longest lived group of mammals. Ate mostly flowering plants.
      • Subclass Theria (Therians) - Mammals which give live birth to their young without a protective shell.
        • Clade Metatheria (Metatherians) - Clade of mammals more closely related to Kangaroos than humans. Many of these species were wiped out along with the Dinosaurs, allowing placental mammals to take their place.
          • Infraclass Marsupialia (Marsupials) - Infraclass of mammals which tend to give birth to relatively undeveloped young and then carry them along in a pouch during infancy.
            • Super Order Australidelphia (Australidelphians) - Australidelphians
              • Order Dasyuromorphia - Order consisting of Australia's predatory marsupials.
        • Clade Eutheria (Eutherians) - Broad infraclass including placental mammals and close relatives.
          • Infraclass Placentalia - Infraclass of Mammals that contain a Placenta. They arose quickly after the demise of the dinosaurs, the first fossils found 1000,000 years after the extinction.
            • Order Proboscidea (Proboscideans) - Mammals with trunks.
            • Order Primates (Primates) - Mammals with long arms.
            • Super Order Laurasiatheria (Laurasiatherians) - Four legged mammals evolved on Laurasia.
              • Order Perissodactyla (Odd-Toed Ungulates) - Hooved animals with and odd number of toes, including horses and rhinoceroses.
              • Order Artiodactyla (Even-Toed Ungulates) - Hooved animals with 2 or 4 toes. Includes deer and cattle.
              • Order Carnivora (Carnivorans) - Order of carnivorous placental mammals, including cats, dogs, and bears.

Therians In the News[]

Mammal Diversity Exploded Immediately After Dinosaur Extinction (Dec 2015)[]

Mammals Were Almost Wiped Out Too (Dec 2014)[]