monotreme

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short-beaked echidna (Tachyglossus aculeatus)

Short-beaked echidna (Tachyglossus aculeatus)

western long-beaked echidna (Zaglossus bruijni)

mammal phylogeny

Tree of life illustrating the three-domain classification of life-forms

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monotreme summary

monotreme: Facts & Related Content

Written and fact-checked by The Information Architects of Encyclopaedia Britannica

Facts

Also Known As	Monotremata

Photos

short-beaked echidna (Tachyglossus aculeatus)

Short-beaked echidna (Tachyglossus aculeatus)

western long-beaked echidna (Zaglossus bruijni)

mammal phylogeny

Tree of life illustrating the three-domain classification of life-forms

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Topics

echidna platypus Ornithorhynchidae Kollikodontidae Steropodontidae oviparity mammal carnivore marsupial placental mammal primate artiodactyl perissodactyl cetacean bat 9 of the World’s Deadliest Mammals rodent

Young chimpanzee dressed in a shirt and sweater vest, scratching his head thinking. (primates)

Wild Words from the Animal Kingdom Vocabulary Quiz

Sea otter (Enhydra lutris), also called great sea otter, rare, completely marine otter of the northern Pacific, usually found in kelp beds. Floats on back. Looks like sea otter laughing. saltwater otters

Animal Group Names

Lion (panthera leo)

Deadliest Animals Quiz

Mute swan with cygnet. (birds)

Match the Baby Animal to Its Mama Quiz

The bearded vulture (Gypaetus barbatus) is seen in Switzerland on December 2024

Animal Factoids