Coffee is the magic elixer that helps us get through the stress of exams. However it is always assumed to be bad for you. Sci & Tech writer Nikita Sall reports on the truth about coffee consumption: is it good or bad?Written by nikitasall1 on 11th June 2018
Creature Feature: The Platypus
This week is the well-known platypus, a seemingly mix-and-match of different animal body parts. In reality, an interesting life history has led to this mammal having such obscure features. Ellen Daugherty reports
Collective noun: A Paddle
Although the platypus is indeed a mammal, it has various reptilian features, such as webbed feet and the ability to lay eggs. This has come about because of the splitting event where the monotremes (mammals that lay eggs) diverged from the mammalian lineage. The monotreme order contains the platypus and four species of echidna, and are all indigenous to Australia and New Guinea.
Mammal-like reptiles would have diverged from the birds and reptiles around 280 million years ago, and monotremes would have diverged from this mammalian lineage around 200 million years ago. They split off from the mammals before the evolution of the placenta, thus they lay eggs, and still retain a strange mix of mammalian and reptilian characteristics. “
“They use the electrical impulses to locate objects and prey, such as freshwater shrimp and crayfish...
Platypus’, and its fellow monotremes, are the only group of land mammals to have evolved electroreception as a tool for predation. The only other mammal that uses this is the dolphin. Their bills, a reptilian feature, are covered in receptors that detect vibrations and small electric currents, called mechanoreceptors and electroreceptors. These allow for accurate navigation in the dark waters. They use the electrical impulses to locate objects and prey, such as freshwater shrimp and crayfish, when swimming underwater. They are naturally buoyant and can stay underwater for a maximum of 2 minutes.
The platypus is also one of the few mammals to excrete venom, which is usually seen in the likes of spiders and snakes. The males release venom out of the back of their hind heel, through a venom gland called a spur. It is thought the venom is released during the breeding season only, suggesting it could be used for competition against other males, rather than a method to stun prey. The function of the venom is to lower blood pressure, which causes pain, and increase blood flow around wounds. Although potentially strong enough to temporarily paralyse small animals, it would not be lethal to humans.
Baby platypus’ are called puggles, and are nursed for 3/4 months by their mother before they are able to swim on their own. Unlike other mammals, the females do not feed their young through teats, but the milk is secreted through pores in their abdomen. The puggles are born with teeth, but these drop out at a very young age, and leave hard plates in the mouth to grind their food.
The platypus is an unbelievably interesting mammal, with its array of traits combining to create a creature unlike any other.