英語時差:罕見的寶藏

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Most people searching for buried treasure would be looking for silver and gold, ancient coins or rare artwork.   

But scientists studying the extinct giant moa bird and its environment are looking for a different kind of artifact. Poop. 

That's right. A treasure trove of information can be found in fossilized feces, commonly called coprolites. The Giant Moa of New Zealand is a great species to study because they stood about nine feet high, weighed close to five-hundred pounds and some of their feces were over six inches in length. 

Now, that's a big piece of treasure. There were once ten species of moa birds in New Zealand, but they were hunted to extinction when Polynesians moved to the island in the 1500s. They were flightless birds, similar to ostriches and emus. Scientists assumed they were herbivores, eating a diet of plants and seeds. But it wasn't until they began studying moa coprolites that they discovered what the birds actually ate and how they affected their environment. 

Scientists expected a bird as large as the moa would eat shrub and tree parts. Moa droppings told a different story. Moas grazed mostly on tiny herbs no more than a foot high. Not only that, many of those herbs are rare or threatened today. Scientists think this is because while the moa ate the plants, it also swallowed seeds whole. Those seeds passed through the digestive tract and were scattered across the countryside to find new places to grow. 

Moa poop has revealed important clues about the moa and its environment. Now, scientists hope to use what they've learned from the moa to make predictions about our own changing world.