Platypus (Ornithorhynchus anatinus)
The platypus can only found in eastern Australia in small rivers and streams. Back when it was first taken to Europe for study, many believed it to be some kind of hoax, as if a beaver’s body had been sewn together with a duck’s bill somehow. They were hunted for their fur until the early 20th century, but now they’re a protected species and have even been featured on the Australian 20 cent coin.
The supposed ancestors of the platypus are reptiles that modified their salivary glands for venom delivery. Fossil records reveal that platypus-like creatures lived long before the Age of Mammals, and that those early platypuses also had teeth during their adult phase, while their descendants seem to have replaced them with horny plates instead.
The eyes of the platypus seem to resemble those of Pacific hagfish or Northern Hemisphere lampreys than those of most tetrapods, and they also feature double cones, which most mammals do not have.
The platypus is in many ways like the beaver, since they’re both furry, aquatic creatures with webbed feet and a large, flat tail. But platypuses, unlike beavers, are monotremes and have a common vent for both waste and reproduction. Their appearance is one of the most unusual ones that can be found in nature since, besides having their beaver-like tail, they’re also duck-billed, they lay eggs (Prototheria,) and have otter-like fur and webbed feet.
Platypuses and echidnas are two of the only five species in the world classified as monotremes: mammals that lay eggs instead of giving birth. Females platypuses can lay from two to four eggs at once, which require incubating for the two following weeks.
The curious platypus is a semi-aquatic mammal and an excellent swimmer that can dive underwater for as long as 30 seconds while looking for food (such as worms, insects, and freshwater shrimp) before having to go back up for hair. They keep both their eyes and ears closed while they’re under water, so they use their electroreception and dig up muddy river beds with their bills to sense the electric fields of their prey while hunting each night. Afterwards, they use the pouches in their cheeks to carry their prey back to the surface so they can feed from it.
Platypuses can live more than 12 years in the wild, unless they cross paths with any of their natural predators, which feature snakes, water rats, hawks, owls, eagles and eventually crocodiles.
While both male and female platypuses are born with ankle spurs, only the male ones can produce and spur venom from their crural glands, while the female ones have rudimentary spur buds that don’t even develop, just like echidnas, and also lack functional crural glands. The male platypuses’ venom production rises especially during the breeding season so they may use it as an offensive weapon to assert their dominance.
These defensin-like proteins (DLPs) are produced by the platypuses’ immune system and used as defensive venoms powerful enough to even kill small animals (such as dogs) and make humans feel a long-lasting hyperalgesia (heightened sensitivity to pain) that can leave them paralyzed for weeks and even incapacitated for months.
Cover image via Reddit.