What is another word for Subclass Prototheria?
Pronunciation: [sˈʌbklas pɹˌə͡ʊtə͡ʊθˈi͡əɹɪə] (IPA) 
Subclass Prototheria is a group of mammals that lay eggs instead of giving birth to live offspring. This subclass is also known as monotremes, which comes from the Greek words "monos" meaning single and "trema" meaning hole. Monotremes only have one opening, known as a cloaca, for excretion, reproduction, and laying eggs. Some other synonyms for the Subclass Prototheria include primitive mammals, egg-laying mammals, and monotrematous mammals. While there are only five extant species of monotremes, they are unique and fascinating creatures that provide valuable insight into the evolution of mammals.
