雅思阅读 116: The Lizard That Swam Like a Whale（像鲸一样游泳的鱼龙）

改编自 University of Bristol / Smithsonian Magazine（2024年4月）。雅思阅读 Section 3 难度，约 1050 词。 素材来源：https://www.bristol.ac.uk/news/2024/april/giant-ichthyosaur-discovery.html

Reading Passage

A. On a grey stretch of the Somerset coast, where the River Severn meets the Bristol Channel, rocks laid down in the age of dinosaurs crumble onto the beach at every high tide. In 2020, an eleven-year-old girl called Ruby Reynolds was walking these shores with her father, Justin, when she spotted a small, dark piece of stone that did not look like the ordinary shingle around it. It was bone. The family returned, found a second fragment half-buried in the mud slope — twice as long, and far better preserved — and kept collecting through 2022. The pieces they recovered eventually turned out to be part of the lower jaw of an animal whose existence rewrote the record books. The complete jaw, scientists concluded, would have stretched at least seven feet long. In April 2024, a team led by the palaeontologist Dean Lomax named the creature Ichthyotitan severnensis: the giant fish-lizard of the Severn. Its estimated length, around eighty-two feet, rivals that of a blue whale, making it the largest marine reptile ever described. The beach where it was found is a working, eroding cliff line rather than a museum quarry, and the fossils emerge a few kilograms at a time, washed out of a mudstone laid down when the sea covered what is now western England.

B. Ichthyosaurs are among the strangest successes in the history of back-boned animals. They were reptiles — air-breathing, cold-blooded descendants of land-living ancestors — that returned to the sea and, over millions of years, evolved into something that looked, and presumably swam, like a dolphin or a shark. Their bodies were streamlined, their jaws long and toothed, their limbs remodelled into paddles. Some species were no bigger than a porpoise; others grew to sizes that dwarf modern whales. They dominated the oceans for much of the Triassic and Jurassic, appearing long before the great sea raptors of dinosaur posterity. The Somerset fossils come from rocks of the latest Triassic, laid down roughly two hundred million years ago, just before a mass extinction erased many of these giants and cleared the water for later reptile hunters. The new find suggests that truly enormous ichthyosaurs were cruising British seas right up to the eve of that catastrophe.

C. It is worth dwelling on how little of such a giant usually survives. Eighty-two feet of soft tissue and muscle does not turn to stone; it rots, sinks, and is scattered. What the Reynolds family found was a single element of the lower jaw — the surangular — measuring more than two metres. Even so, the fragment was so large that a similar bone recovered near Lilstock in 2018 had originally been misidentified as a dinosaur bone, until comparison with better-known ichthyosaurs showed what it really was. Size alone is a rough ruler. To estimate the total length of an animal from a jaw fragment, researchers measure the equivalent bone in smaller, more completely known ichthyosaurs and scale up the proportion. The method is honest about its uncertainty: different reference species yield different estimates, which is why scientists describe the Somerset animal as "up to" eighty-two feet rather than precisely eighty-two. The result remains the largest marine reptile yet placed on the evolutionary tree, but it rests on a few square metres of rock rather than a skeleton.

D. The discovery also reshapes a familiar argument about gigantism. Palaeontologists have long known that ichthyosaurs reached huge sizes, but the timing was debated. Some evidence suggested that only the middle Triassic forms, from beds in the Swiss Alps and elsewhere, achieved whale-like proportions, while the latest Triassic seas were already shrinking back toward more modest reptiles. The Somerset surangular — and the still larger piece from 2018 — push that window forward. Giant ichthyosaurs, it now seems, were present in British waters almost to the very end of the Triassic, meaning gigantism persisted rather than retreated. That is a striking claim, because the end-Triassic extinction was one of the most severe crises in the history of life, and surviving it at whale size is no small feat. Researchers have described the animal ecologically as the "killer whale" of its time: a fast, high-tier predator occupying the same apex role that orcas play in today's oceans. That picture rests on its size, its long, tooth-lined jaw and the food web of the ancient seabed, but it is an inference from anatomy, not a direct observation of behaviour. No ichthyosaur was ever seen hunting, and all such reconstructions are acts of disciplined imagination.

E. What happens next illustrates how fragmentary fame can be. The Somerset coast is still eroding, and the next tide could expose more of Ichthyotitan — a shoulder, a paddle, vertebrae that would pin down the size estimate that today rests on a jaw. Museums now treat the beach as a site to watch, and amateur collectors, whose eyes first found the bone, have shown once again how much rests on people willing to look at a muddy slope and wonder. For all its fame, the creature remains a puzzle. We know it was enormous, that it breathed air, and that it swam in warm shallow seas where England now stands. We do not know what it ate in its final years, how it raised its young, or why its kind vanished so completely that no descendant survived into the modern ocean. A single jawbone, however carefully scaled, can open a question without closing it — and that, for a field built on fragments, is precisely how the next discovery begins. The cliffs keep crumbling, the tides keep giving up what they hid for two hundred million years, and the next surangular may, one morning, wash straight into the path of another pair of untrained eyes.

Questions 1-4

Choose the correct heading for paragraphs B, C, D and E from the list of headings below.

List of Headings i. What ichthyosaurs were — and how odd they became ii. How an eleven-year-old girl found a dinosaur tooth iii. Estimating an eighty-two-foot animal from a jawbone iv. Giantism persisted later than once thought v. What the next tide might reveal vi. The anatomy of a blue whale vii. Why the Triassic extinction was caused by humans

1. Paragraph B: ____
2. Paragraph C: ____
3. Paragraph D: ____
4. Paragraph E: ____

Questions 5-8

Choose the correct letter, A, B, C or D.

5. How was Ichthyotitan discovered? A. A professional expedition found a complete skeleton. B. An eleven-year-old girl and her father found jawbone fragments on a beach. C. A mining company uncovered it by accident. D. It was found in a museum's basement.

6. What is an ichthyosaur? A. A land dinosaur that ate fish. B. An air-breathing marine reptile that evolved a dolphin-like shape. C. A type of modern whale. D. A giant prehistoric shark.

7. How do scientists estimate the total length from a jaw fragment? A. By guessing without evidence. B. By scaling the equivalent bone from smaller, more complete ichthyosaurs. C. By measuring the water depth at the site. D. By carbon-dating the mud.

8. Why does the discovery matter for the timeline of gigantism? A. It shows giant ichthyosaurs persisted almost to the end of the Triassic. B. It proves ichthyosaurs were never large. C. It moves giantism back to the Jurassic. D. It shows the animal was a plant-eater.

Questions 9-13

Do the following statements agree with the claims of the writer?

Write:

• TRUE if the statement agrees with the information
• FALSE if the statement contradicts the information
• NOT GIVEN if there is no information on this

9. The complete lower jaw of Ichthyotitan would have stretched at least seven feet.
10. The Somerset fossils date from the middle Jurassic period.
11. The 2018 Lilstock bone was immediately recognised as an ichthyosaur jaw.
12. Scientists are certain exactly what Ichthyotitan ate in its final years.
13. Ichthyotitan is smaller than a modern porpoise.

Questions 14-15

Complete the summary below using NO MORE THAN TWO WORDS from the passage.

Ichthyotitan's estimated length of around eighty-two feet rivals that of a (14) __________, making it the largest marine (15) __________ ever described.

答案与解析

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