mono·​treme | \ ˈmä-nə-ˌtrēm How to pronounce monotreme (audio) \

Definition of monotreme

: any of an order (Monotremata) of egg-laying mammals comprising the platypuses and echidnas

Examples of monotreme in a Sentence

Recent Examples on the Web Content includes video, images, and questions designed to teach students about mammals, birds, primates, bears, reptiles, monotremes, marsupials and others. Tracy Maness, Houston Chronicle, "San Diego Zoo Global offers free online courses during pandemic," 6 Apr. 2020 Males of the Australian monotremes — egg-laying mammals — produce venom in their thighs during mating season and deliver the poison to competitors via hollow spurs just above their webbed feet. 8. Gemma Tarlach, Discover Magazine, "20 Things You Didn't Know About ... Poison," 25 Sep. 2018 The platypus is part of a small group of animals called monotremes, which lay eggs and produce milk to feed their young. Maria Clark,, "Platypus milk could be a weapon to fight infection: Report," 19 Mar. 2018 Around 80 million years later, the monotremes—or egg-laying mammals—split off from the mammalian lineage, says Rebecca Young, a biologist at the University of Texas at Austin. National Geographic, "How the Venomous, Egg-Laying Platypus Evolved," 30 July 2016 There are three kinds of mammals: egg-laying monotremes such as the platypus, marsupials like kangaroos and opossums, and the majority—placental, or eutherian, mammals—including humans and about 4400 other mammal species. Elizabeth Pennisi, Science | AAAS, "Digital reconstruction of ancient chromosomes reveals surprises about mammalian evolution," 19 June 2017 Though monotremes' fossil record is limited, some skulls have been found, such as the extinct Obdurodon dicksoni. National Geographic, "How the Venomous, Egg-Laying Platypus Evolved," 30 July 2016

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'monotreme.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of monotreme

1835, in the meaning defined above

History and Etymology for monotreme

New Latin Monotremata, from Greek mon- + trēmat-, trēma hole — more at trematode

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Time Traveler for monotreme

Time Traveler

The first known use of monotreme was in 1835

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Cite this Entry

“Monotreme.” Dictionary, Merriam-Webster, Accessed 2 Dec. 2020.

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mono·​treme | \ ˈmän-ə-ˌtrēm How to pronounce monotreme (audio) \

Medical Definition of monotreme

: any mammal (as a platypus) of the order Monotremata

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