Mammal
Videos
A mammal is a vertebrate animal of the class Mammalia. Mammals are characterized by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or
Restoration of Juramaia sinensis, the oldest-known eutherian (160 mya)
Fossil of Thrinaxodon at the National Museum of Natural History
Hyaenodon horridus at the Royal Ontario Museum. The genus Hyaenodon was among the most successful mammals of the late Eocene-early Miocene epochs spanning for most of the Paleogene and some of the Neogene periods, undergoing many endemic radiations in North America, Europe, and Asia.
Sexual dimorphism in aurochs, the extinct wild ancestor of cattle
Monotreme
Videos
Monotremes are mammals of the order Monotremata. They are the only mammals still in existence which lay eggs, rather than bearing live young. The five extant monotreme species are the platypus and the
Mammal
…lifespan varies from two years for the shrew to 211 years for the bowhead whale. All modern mammals give birth to live young, except the five species of monotremes, which lay eggs. The most species-rich group is the viviparous placental mammals, so named for the temporary organ (placenta) used by offspring to draw…
Monotreme collage
Platypus
Short-beaked echidna
A model of the extinct monotreme Steropodon at the Australian Museum