As we all know, mammals are not the group of animals known for laying eggs. In fact, there are pretty much no mammals that give birth through egg laying...except for the monotremes of course! So what exactly are monotremes you ask? Well first off, they are indeed mammals, so no birds or reptiles or insects here. And yes, they lay eggs! Unlike the majority of mammals that give live birth, monotremes are oviparous animals, which means they lay eggs to reproduce. They are one of the 3 classifications of mammals, and here are some more detailed on facts on what makes monotremes unique.
- All living monotremes are indigenous to New Guinea and Australia. There is evidence that some species lived in South America, however there is nowhere else in the world where these mammals can be found in the wild.
- The only living monotremes we have left are the duck-billed platypus, and the 4 species of echidna that exist.
- The word "monotreme" comes from Greek, and translates to "single hole", referring to the cloaca which is the only opening monotremes have for expelling waste as well as reproducing.
- While all mammals are endothermic, monotremes have a much lower metabolic rate and body temperature than other mammals - the platypus has an average temperature of 88 degrees, while marsupials are around 95, and placental mammals around 99