monotreme
🇺🇸
/ˈmɑːnətriːm/
🇬🇧
/ˈmɒnətriːm/
A mammal that lays eggs instead of giving birth to live young, like the platypus and echidna.
The discovery of the monotreme in Australia was a significant event in the study of mammalian evolution.
在澳大利亚发现单孔类动物是哺乳动物进化研究中的一项重要事件。