• Audience
    Secondary school, Tertiary
  • Learning stage
    Stage 4, Stage 5, Stage 6
  • Curriculum area
    Science (Biology)
  • Resource type
    Poster

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The Platypus is a type of egg-laying mammal called a monotreme. It is one of two species of monotreme that live in Australia, the other being the Short-beaked Echidna. The monotremes diverged from other mammals about 166 million years ago and today the platypus is one of the most evolutionarily distinct animals on Earth. It lives in freshwater systems along the east coast of Australia, but fossil evidence shows that platypuses used to have a wider distribution.


  • A baby platypus is called a puggle.
  • Platypuses have teeth when they are born, but as they mature their teeth are replaced by specialised dental pads made of keratin. Keratin is a type of protein that is also found in your fingernails.
  • Platypuses also once lived in what is now South America.

  1. How many extinct species of platypus have been discovered?
  2. Which body part has been most often fossilised? Why do you think this is?
  3. How old is the Riversleigh platypus? How is this fossil different from other platypus fossils?
  4. On which continents have platypus fossils been found?
  5. How can the Theory of Continental Drift explain the distribution of fossils in South America and Australia?

The platypus family tree has been difficult to piece together because fossils are very rare. This poster summarises the information we know about platypus fossils that have been found, including the location of the fossil site and the age of the fossils. Students can use this poster as a secondary source of information to learn about the macroevolution of platypuses.