Platypus

The platypus is one of the most unusual mammal species alive. Along with echidnas, it belongs to the most primitive mammalian group, known as Monotremes (Monotremata). All monotremes share a unique anatomical feature with birds: a single opening for both the digestive and reproductive tracts, unlike other mammals, which have separate openings for these systems. Native to Australia, the platypus inhabits streams and rivers, where it hunts small aquatic animals using highly sensitive sensors located on its bill. While this structure resembles a bird's beak, it is actually a modified mammalian jaw. Male platypuses are among the few venomous mammals, possessing venomous spurs on the back of their hind feet. While the venom is not life-threatening to humans, it can cause significant pain. Platypus reproduction is particularly fascinating. Unlike most mammals, the platypus does not give birth to live young; instead, it lays eggs with soft shells, similar to reptile eggs. The female digs a deep burrow in a riverbank to lay her eggs. After hatching, the young nurse on milk like other mammals, but the mother lacks teats. Instead, milk seeps through the skin and fur, where it is licked up by the young.