monotreme

(noun)

a mammal that lays eggs and has a single urogenital and digestive orifice; only the echidnas and platypuses

Related Terms

Examples of monotreme in the following topics:

  • Living Mammals

    • Living mammals can be classified in three subclasses: eutherian, metatherians and monotremes.
    • Living mammals can be classified into three major classes: eutherians, monotremes, and metatherians.
    • Monotremes form their sister clade.
    • Monotremes are unique among mammals as they lay eggs rather than giving birth to live young.
    • Additionally, monotremes have no teeth.

  • Evolution of Mammals

    • Synapsids from this period include Dryolestes (more closely related to extant placentals and marsupials than to monotremes) as well as Ambondro (more closely related to monotremes).
    • One of the major differences between placental and nonplacental eutherians is that placentals lack epipubic bones, which are present in all other fossil and living mammals (marsupials and monotremes).

  • Characteristics of Amniotes

    • Most mammals do not lay eggs (except for monotremes).

  • Parasitic Skin Diseases

    • They are obligate ectoparasites of every avian and mammalian order except for monotremes (the platypus and echidnas), bats, whales, dolphins, porpoises, and pangolins.

  • Characteristics of Mammals

    • While male monotremes and eutherians possess mammary glands, male marsupials do not.