Dino Gangs: Dr Philip J Currie’s New Science of Dinosaurs. Josh Young. Читать онлайн. Newlib. NEWLIB.NET

Автор: Josh Young
Издательство: HarperCollins
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Жанр произведения: Природа и животные
Год издания: 0
isbn: 9780007413409
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else going on to reduce their diversity, and I suspect it was climatic.’

      ‘There is no black or white in palaeontology, only differing shades of grey.’

      Further, Currie argues, if an asteroid hit and simultaneously wiped out all the dinosaurs, then there should be an abundance of fossils present on the Cretaceous–Tertiary boundary. However, the preserved evidence does not show this. In North America, the fossil record shows that only a few dinosaurs, including Ankylosaurus, Triceratops and Tyrannosaurus, lived until the end of the Cretaceous period. Studying the succession of faunas over a 10-or 15-million-year period shows that species’ diversity was dropping off.

      ‘Prior to the asteroid hitting, something else was going on,’ Currie reasons. ‘It’s like everything: as humans what we do is try to come up with a simple answer, but in nature there is not necessarily a simple answer.’ He acknowledges that this is just one of many theories on extinction. ‘It’s very easy to come up with a new theory for dinosaur extinction; it’s not so easy to go out and get the evidence. The problem is that it takes years and years of collecting evidence.’

      The same can be said about almost all dinosaur theories. There is no black and white in palaeontology, only differing shades of grey. Short of having a time machine to travel back to the Jurassic or Cretaceous periods, palaeontologists must take to the field and dig for evidence, and then hold new fossil finds up against existing ones. Eureka moments are very rare. Discoveries take years to be prepared, studied and then scientifically described before they are presented to the public for further debate. Even under the best of circumstances, they are met with doubting eyes and contradictory theories rather than front-page headlines.

      chapter 2

      the dino hunters

      The special group of palaeontologists loosely known as dinosaur hunters are detectives who spend their lives trying to put together pieces of an ancient mystery that may never be fully solved. The dino hunter is part historian, part explorer, part scientist. He attempts to reconstruct history which dates back more than 65 million years – or 60 million years before the first human – through a combination of research, fieldwork and lab work. To do so he must raise public and private money to fund expeditions, navigate foreign government bureaucracies to gain access to critical sites, endure the harsh conditions of some of the most brutal climates on earth, outsmart poachers looking to make a buck on the black market, and recruit young palaeontologists to assist in the field and the lab.

      Dinosaur finds can be traced to the ancient times of the Western Jin Dynasty of China, when they were thought of as ‘dragon bones’, although the first identified dinosaur find occurred in 1676, in England. Part of a large bone was found in a limestone quarry at Cornwall and described the following year by Oxford professor Robert Plot as the femur of a large animal like an elephant. However, some people concluded later that it must have belonged to a giant human like those written about in the Bible. It wasn’t until 1824 that the first scientific description of a dinosaur was written by another Oxford professor, William Buckland. After collecting a large number of dinosaur bones over a nine-year period, Buckland determined they were all from a related animal that resembled a giant lizard, and he published a scientific paper describing a great fossilized lizard that he named Megalosaurus. Although this was the first dinosaur described, the term ‘dinosaur’ wasn’t coined until 1842 when Richard Owen recognized that the remains shared a number of features and therefore should be grouped together taxonomically.

image

      An artist’s impression of the duckbilled dinosaur Corythosaurus.

      Jaime Chirinos/Science Photo Library

      The first recorded North American dinosaur find was made in 1838 by John Estaugh Hopkins in a mudstone quarry on the Cooper River in Haddonfield, New Jersey. Hopkins displayed in his house the bones he found, where they were seen by his friend William P. Foulke, a part-time geologist. Foulke returned to the quarry and discovered most of a skeleton, which he asked palaeontologist Joseph Leidy to help him extract and study. Leidy scientifically described the find and named it Hadrosaurus foulkii, or ‘bulky reptile’. The Hadrosaurus find would lead to what became known as the ‘bone wars’ which erupted between dinosaur hunters Othniel Charles Marsh and Edward Drinker Cope, who were both mentored by Leidy.

      Marsh, of Yale University’s Peabody Museum of Natural History, and Cope, of the Academy of Natural Sciences in Philadelphia, were initially cordial and shared information on their finds. But a dispute broke out over a fossil site that was discovered by Cope just south of the Haddonfield site. Cope was having the site’s new finds sent to him for examination, but when Marsh realized there were an untold number of bones to be recovered, he began paying those digging the site to divert the finds to him. Cope found out about Marsh’s underhanded tactics, and the gloves came off.

      For the next 20-plus years, Marsh and Cope used all means available – including bribery and theft – to outdo one another in the search for dinosaur bones. Both men spent considerable sums of money trying to win the ‘bone wars’ and to be recognized as the undisputed leader in the new field of dinosaur palaeontology. Marsh was backed by a wealthy uncle, George Peabody, the financial backer of Yale’s Peabody Museum, while Cope used his considerable family money. Some of their work was rushed and sloppy. Marsh named both Apatosaurus in 1887, and Brontosaurus in 1889. He did not have a skull for the latter and when it was mounted, a Camarasaurus skull was put on it. Eventually it was discovered that (other than the Camarasaurus skull) Apatosaurus was the correct name for both specimens. Cope made a similar hurried mistake on Elasmosaurus. Despite the duo’s lack of professional ethics, they found an exceptional number of specimens and localities for future study. Marsh was credited with discovering 80 new dinosaur species and Cope named 56 – and a competitive stage was set for future dino hunters.

      Two of the most famous dino hunters who followed them (but who did not resort to underhanded tactics) were Barnum Brown and Roy Chapman Andrews. Brown, who was named after the legendary circus showman P.T. Barnum, was the American Museum of Natural History’s main dinosaur collector in the early 1900s. He is best known as the man who discovered Tyrannosaurus rex in 1902 in the Hell Creek Formation in south-eastern Montana. Several years after that landmark find, he travelled to Alberta, Canada and led an expedition down the Red Deer River that discovered, among other dinosaur fossils, several Albertosaurus hind feet in the same location, which he had shipped back to the Museum of Natural History.

      Andrews was an adventurer who also worked for the American Museum of Natural History and later became its director. He began his natural history quest studying whales in the coastal waters near Vancouver Island in British Columbia, where he collected the skeleton of a humpback whale. He next convinced the museum’s director, Henry Fairfield Osborn, to fund the first expedition to the Gobi Desert in Mongolia to search for the origins of man. Though Andrews failed to find any evidence of early man over the course of five expeditions from 1922 to 1930, he and his team found reams of dinosaur skeletons, among them the first Protoceratops, Oviraptor and Velociraptor. On their expedition in 1923, they identified the first fossilized dinosaur eggs, which were initially thought to be those of Protoceratops but were identified in 1995 as Oviraptor eggs.

      The work of Brown and Andrews set the standard for future dino hunters. Their finds were remarkable in their time, but they would become even more important as they were re-examined by future palaeontologists. Their work inspired and informed a group of palaeontologists who would revolutionize the discipline in the late 1970s and would ultimately galvanize public interest in dinosaurs.

      ‘The reason that the world needs palaeontologists is because, just think about it: if you go back 68 or 70 million years ago, the largest animal on land was a dinosaur, and mammals were very small,’ palaeontologist Louis Jacobs explains. ‘If you go to Africa now, the largest land animal in the world is an elephant, a mammal, and you can go and you can see a bird sitting on top of an elephant. That’s a dinosaur on top of a mammal. So what’s happened in the last 65 million years is the entire ecological arrangement of life has changed, and if we can understand how that ecological arrangement of life has changed and why it changed, that tells us about