Why the Platypus is so weird

Despite being categorized as a mammal, the semiaquatic Platypus lays eggs instead of giving birth directly to its babies.

It sweats Milk and is covered under the venomous spurs. One of the rarest features of this mammal is owning 10 sex chromosomes.

“The complete genome has provided us with the answers to how a few of the platypus’ bizarre features emerged. At the same time, decoding the genome for platypus is important for improving our understanding of how other mammals evolved—including us humans,” says Guojie Zhang, a professor in the biology department at the University of Copenhagen.

“It holds the key as to why we and other Eutheria mammals evolved to become animals that give birth to live young instead of egg-laying animals.”

Platypus lays eggs instead of giving birth direct to its babies 

Despite being grouped with monotremes that existed million years before the emergence of modern-day mammals, the Platypus lays eggs instead of giving birth directly to its babies.

“Indeed, the platypus belongs to the Mammalia class. But genetically, it is a mixture of mammals, birds, and reptiles. It has preserved many of its ancestors’ original features—which probably contribute to its success in adapting to the environment they live in,” Zhang says.

“It informs us that milk production in all extant mammal species has been developed through the same set of genes derived from a common ancestor which lived more than 170 million years ago—alongside the early dinosaurs in the Jurassic period,” Zhang says.

10 Sex Chromosomes

A total of 10 sex chromosomes are found in the monotremes. With 5 Y and 5 X Chromosomes, it shares the platform with every mammal available on the Earth.