prototherian

/ˌproʊtəˈθɪriən/
noun
  1. A mammal belonging to the group that includes egg-laying mammals such as the platypus and echidna.
    • Prototherians are different from other mammals because they lay eggs instead of giving birth to live young.
    • The platypus is a well-known prototherian found in Australia.
    • Scientists study prototherians to learn about the early evolution of mammals.
Synonyms
Antonyms
adjective
  1. Relating to the group of egg-laying mammals (monotremes).
    • Prototherian species have been around for millions of years.
    • The fossil shows prototherian features that are not seen in modern marsupials.
    • The prototherian reproductive system is unique among mammals.
What does "prototherian" mean? | whatsthatwordmean | whatsthatwordmean