monotreme

[ mon-uh-treem ]

Phonetic (Standard)IPA

noun

any animal of the Monotremata, the most primitive order of mammals, characterized by certain birdlike and reptilian features, as hatching young from eggs, and having a single opening for the digestive, urinary, and genital organs, comprising only the duckbill and the echidnas of Australia and New Guinea.

monotreme

/ ˈmɒnəʊˌtriːm; ˌmɒnəʊˈtriːmətəs /

any mammal of the primitive order Monotremata, of Australia and New Guinea: egg-laying toothless animals with a single opening (cloaca) for the passage of eggs or sperm, faeces, and urine. The group contains only the echidnas and the platypus

monotreme

/ mŏn′ə-trēm′ /

Any of various mammals of the order Monotremata. Monotremes are the most primitive type of living mammal. They lay eggs and have a single opening (cloaca) for reproduction and elimination of wastes. The females have no teats but provide milk directly through the skin to their young. The only living monotremes are the duck-billed platypus, found in Australia and New Guinea, and the echidnas, found in New Guinea. Monotremes may have evolved already in the Jurassic Period, but the precise nature of their relationship to marsupials and placental mammals is disputed.

1825–35; < French monotrème < New Latin monotrema, assumed singular of Monotremata, neuter plural of monotrematus monotrematous

C19: via New Latin from mono- + Greek trēma hole

Pseu′dodont, having false teeth, as a monotreme; Pseu′dodox, false.

The oviparous monotreme and the marsupial almost certainly represent lower mammalian ancestral stages.

Moreover, it requires a large amount of material to form a mammalian egg, such as that of the monotreme.

One monotreme egg represents more economy and saving than a thousand eggs of a worm.

It is enough that the living Monotreme and Marsupial so finely illustrate the transition from a reptilian to a mammalian form.

April 19, 2024tortuous

[tawr-choo-uhs ]

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