The Platypus: Built for Two Worlds
The Platypus: Built for Two Worlds
When the first platypus specimen reached Britain in the late 1700s, some scientists suspected a hoax. An animal with the bill of a duck, the tail of a beaver and the fur of an otter seemed too unlikely to be real. [ 1 ] Today we know that the platypus is very real, and that each of its strange features helps it to survive both in rivers and on land.
The platypus spends much of its time hunting in the water, usually at night or around dawn and dusk. When it dives, folds of skin close over its eyes and ears, and its nostrils seal shut. [ 2 ] Its bill is covered with thousands of tiny sensors that detect the faint electrical signals given off when its prey, such as insect larvae, shrimps and worms, move their muscles. By sweeping its bill from side to side, the platypus can find food hidden in the mud of the riverbed.
An adult platypus has no teeth. Instead, it stores its catch in pouches in its cheeks and carries it up to the surface. [ 3 ] It then grinds the food between hard pads in its mouth before swallowing.
On land, the platypus lives in burrows dug into riverbanks. Its webbed front feet, so useful for swimming, would make digging awkward, but the webbing can be folded back to reveal strong claws. The female lays her eggs, usually one or two, in a nest of damp leaves at the end of a long burrow, and feeds the young on milk once they hatch. It is this combination, an egg-laying mammal, that once made the platypus seem impossible, and that still makes it one of the most unusual animals on Earth.
Worked explanation 1
Which sentence best fills gap [ 1 ] in the passage?
- AA.
Its bill was the feature they most admired, because it could sense electricity.
- BB.
One examined it closely for stitches, sure that someone had sewn a duck's bill onto another animal's body.
- CC.
As a result, the platypus quickly became the most popular animal in British zoos.
- DD.
Its webbed front feet were the first sign that it could swim.
Answer: B
Answer: B
Read both sides of the gap. Before it, scientists suspect a hoax; after it, 'Today we know that the platypus is very real'. Only B continues the doubt. C does not fit, since people who thought it fake would not make it popular, and A describes what we know 'today', not what the first scientists believed.