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

Therians Web PagesEdit


  • 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.
        • 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 NewsEdit

Mammal Diversity Exploded Immediately After Dinosaur Extinction (Dec 2015)Edit

Mammals Were Almost Wiped Out Too (Dec 2014)Edit

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