Flying Dinosaurs: How Fearsome Reptiles Became Birds
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Mixing colorful portraits with news on the latest fossil findings and interviews with leading paleontologists in the United States, China, Europe, and Australia, John Pickrell explains and details dinosaurs' development of flight. This special capacity introduced a whole new range of abilities for the animals and helped them survive a mass extinction, when thousands of other dinosaur species that once populated the Earth did not. Pickrell also turns his journalistic eye toward the stories behind the latest discoveries, investigating the role of the Chinese black market in trading fossils, the controversies among various dinosaur hunters, the interference of national governments intent on protecting scientific information, and the race to publish findings first that make this research such a dynamic area of science.
ISBN-13: 9780231171786
Media Type: Hardcover
Publisher: Columbia University Press
Publication Date: 09-16-2014
Pages: 240
Product Dimensions: 6.20(w) x 9.30(h) x 0.80(d)
Age Range: 18 Years
John Pickrell is an award-winning science writer and the editor of Australian Geographic magazine. He has worked in London, Washington, D.C., and Sydney for numerous publications, including New Scientist, Science, Science News, and Cosmos. He has been a finalist for the Australian Museum's Eureka Prizes three times, has won an Earth Journalism Award, and has been featured in the 2011 and 2014 editions of The Best Australian Science Writing.
The missing link How the connection between dinosaurs and birds was found – and then lost again for 50 years. Our story begins in the Altmühl Valley in Bavaria, Germany. It looks nothing like Bavaria now, for we have stepped back 147 million years into the past, to the Late Jurassic period, and the land here is part of a subtropical island archipelago much nearer to the equator than today. An ominous-looking afternoon thunderstorm has rolled in and gravid clouds are pelting the shallow lagoons with a torrent of tepid raindrops. The warm waters teem with jellyfish, crustaceans, corals and other invertebrates, as well as fish, crocodiles and large marine reptiles such as ichthyosaurs. Swooping through the skies above are pterosaurs, flying reptiles related to dinosaurs. Along the shoreline a pack of Compsognathus – turkey-sized carnivorous dinosaurs – fluff up their downy feathers and shake themselves in the rain before chirping and darting into the thick cover of the woodland fringe. Another reptile here can fly – or at least a reptile of sorts, for it looks very much like a modern bird. About the size of a raven or a crow, this half-metre-long creature has wings and a feathered tail that seems unusually long for its body. Its flight feathers are pale with dark tips, giving it a pattern something like a magpie. Unlike any modern bird, however, it has a long bony tail, claws on the end of its wings, and teeth. This animal is Archaeopteryx and its species is one of the first birds truly capable of powered flight. Though Archaeopteryx can take to the skies, it has little of the aerial aptitude of a modern bird. Taking off costs it significant energy and effort, and it is prone to ungainly crash landings. The extra weight it carries from its bony tail is only part of the problem, as it also lacks a keeled sternum (or breastbone) and the wing-powering mass of muscle that attaches to this bone in modern birds. In other respects, though, Archaeopteryx is already attuned to flight. Relative to body size, its brain is large, and its cerebral hemispheres and regions used for vision and movement are well developed, giving it a keen sense of sight and spatial awareness. On its hind limbs are feathers that help stabilise it and act as air brakes. This allows the otherwise cumbersome creature to turn more adeptly and fly steadily, so it can negotiate the dense wooded environment; swoop out of the reach of predators; and sneak up on the lizards, frogs, beetles, dragonflies and other insects it feeds upon in these prehistoric forests. The lagoons here sometimes turn stagnant in the heat, and the thick, silty mud that carpets their floors is perfect for preserving – in great detail – the remains of any dead animals that sink into them. Over the millennia many Archaeopteryx do meet their end on the floor of these lagoons, and in the resulting rocks they would surely have remained if not for a phenomenal turn of fate that led Bavarian quarrymen to chance upon some of their delicate imprints 147 million years later. The first bird The first specimen of Archaeopteryx was discovered in Germany, in a slab of Bavarian limestone in 1861, just two years after the publication of Charles Darwin's On the Origin of Species. It is one of the most important fossils ever found. Puzzlingly, the animal preserved in the rock shared many features with theropod dinosaurs but was unmistakably a bird, with perching feet and well- developed flight feathers. Archaeopteryx is a transitional fossil with a mixture of features found in both birds and reptiles, says Paul Barrett of London's Natural History Museum, one of the United Kingdom's foremost dinosaur experts. 'No modern bird has teeth, and no modern bird has a bony tail; both of these are reptilian features. Although it is known definitively as the first bird, early on it would have been recognised that it has these reptilian features, and this was a kind of smoking gun.' Only 11 specimens (and a feather) have ever been found, and the Natural History Museum still has the one first used to describe the species by its then director Professor Richard Owen in 1863. Scientists come from across the world to study the 'London specimen', and it still plays a central role in today's debates about the relationship between early birds and feathered dinosaurs. Many of the other specimens are in German institutions, including the 'Berlin specimen', which is the most beautiful of all. One is in the United States in a private institution. Another is in private hands, presumed lost. One was misidentified as a pterosaur and re-identified as Archaeopteryx by palaeontologist John Ostrom in the 1970s. 'There aren't that many of them, but between all of them we have a fairly good idea of what the skeleton looked like', Barrett says. 'They are different-sized individuals and slightly different ages. It's been suggested that one or two of them might represent a different genus of bird that's closely related to Archaeopteryx, but that's contentious.' Before the discovery of Archaeopteryx, scientists had already realised there were skeletal similarities between birds and reptiles such as crocodiles. But when Darwin published On the Origin of Species in 1859, no transitional fossils had been found. Today, after several centuries of collecting, the fossil record is surprisingly patchy, but in Darwin's day it was even more problematic to use it as evidence for the kind of gradual changes through evolution that he proposed. Instead he looked to living creatures, such as the multitude of closely related Galapagos finches, to make his points more forcefully. In one chapter of his work, where he methodically laid out the flaws in his theory, Darwin noted: But, as by this theory innumerable transitional forms must have existed, why do we not find them embedded in countless numbers in the crust of the earth? ... I believe the answer mainly lies in the record being incomparably less perfect than is generally supposed ... The crust of the Earth is a vast museum; but the natural collections have been made only at intervals of time immensely remote. Then in 1860, with impeccable timing, the fossil of a Jurassic-era feather turned up in a limestone quarry in the Solnhofen region of Bavaria's Altmühl Valley. These fine limestones had been used for building materials and paving slabs as early as Roman times, but had come into their own in the 1700s with the development of lithography, a printing technique that used slabs of the stone engraved with acid. Lithography required only the finest, smoothest slabs, and relied on quarrymen carefully splitting the rock by hand in search of them – the fossils they found of fish, winged insects, shrimps and even pterosaurs were simply a lucrative sideline. The species the feather belonged to was named Archaeopteryx lithographica (literally 'ancient wing, written in stone') by German palaeontologist Hermann von Meyer. The following year a largely complete skeleton, minus the skull, of what appeared to be a puzzling crow-sized bird was given to doctor Karl Häberlein by a sickly quarryman in exchange for medical attention. Squabbling between German bidders led Häberlein to sell the specimen, along with the rest of his extensive fossil collection, to Richard Owen, who paid £700 (about AU$120 000 today). Häberlein, an elderly widower, is rumoured to have used the money to cover a dowry and wedding for his daughter. Though spending such a sum of money seemed unconscionable to the trustees of the museum, it now seems a small figure to have paid to secure what is the institution's most valuable piece. Archaeopteryxand the evolution debate Owen was one of the foremost palaeontologists and anatomists of his day, and was a well-known public figure; he devised the term 'dinosaur' itself in 1842, meaning 'fearfully great, a lizard'. He was also a darling of London's Victorian elite and gave the children of Queen Victoria herself biology lessons. Nevertheless, he was a 'lean-faced, pop-eyed man of pedantic turn of phrase ... notorious for using ridicule and malicious attacks to further his own position', says anthropologist and writer Pat Shipman. A man with deep religious convictions, Owen didn't like Darwin's idea of natural selection one little bit. As biologist Thor Hanson notes, Owen had built his career: on the firm belief that species were created and altered only by the hand of God. If Archaeopteryx could be perceived as an intermediate step between reptiles and birds, it would be dangerous fodder for Darwinists. They would call it evidence that birds and their most distinctive feature, feathers, evolved from reptiles. Within months of receiving the Archaeopteryx fossil in London in 1862, Owen had dashed off a paper in which he made no mention of a missing link, describing the fossil as 'unequivocally a bird' and passing off its reptilian features, such as a tail and teeth, as 'a closer adhesion to the general vertebrate type'. The scene was now set for a battle of wills with his great intellectual rival, the staunch Darwinist Thomas Henry Huxley. History remembers TH Huxley as 'Darwin's bulldog', and he was certainly a vocal champion of the idea of evolution by natural selection, as well as a close friend of Darwin. Huxley was a great evolutionary biologist and comparative anatomist. He was based at the Royal School of Mines, now one of the constituent schools of Imperial College. In contrast to Owen's noted pomposity, Huxley was apparently witty, well liked and a gifted speaker. In 1868 he published his own paper on Archaeopteryx, detailing the remarkable similarities of the fossil to the small dinosaur Compsognathus and arguing that the species was not only the first bird but also a very clear missing link between birds and dinosaurs. He later noted: Birds are modifications of the same type as that on which reptiles are formed, and if this similarity of structure is the result of community of descent, we should expect to find, in the older formations, birds more like reptiles than any existing bird, and reptiles more like birds than any existing reptile. If the geological record were sufficiently extensive ... we ought to find an exact series of links, but this, of course, is hardly to be expected. (Huxley surely couldn't have imagined that with all the recent feathered dinosaur discoveries in China, this 'exact series of links' is precisely what we have found.) In his paper on Archaeopteryx, he also went on to include a withering rebuke of Owen for confusing the left and right leg of the specimen and getting the pelvis the wrong way round. Huxley recognised that the hind parts of bird and dinosaur skeletons are strikingly similar. 'If the whole hind quarters, from the ilium [pelvis] to the toes, of a half-hatched chicken could be suddenly enlarged, ossified, and fossilised as they are', he wrote, 'they would furnish us with the last step of the transition between birds and reptiles; for there would be nothing in their characters to prevent us from referring them to the Dinosauria'. Similarities between Archaeopteryx and Compsognathus – fossils of which are found in the in the same Solnhofen deposits – included the fact that both animals were bipedal, had an upright stance and shared numerous features of their ankle joints. Bipedal – two-legged, rather than four-legged – animals are few and far between, and making the transition requires a complex suite of adaptations, so it has happened rarely in evolutionary history. Full bipedalism has only evolved a handful of times in lineages of modern animals – in kangaroos, rodents, birds and the line leading to humans. Making the switch to two legs also frees up the forelimbs for other purposes – such as making tools or flapping to get into the air – and has therefore been associated with great evolutionary success, but that's something we'll come back to later. Referring to the similarity between the bipedal nature of birds and the dinosaurs Iguanodon and Megalosaurus, Huxley noted: When we consider what a very strong piece of evidence this is, we are forced to the conclusion that the evolution of birds from reptiles, by some such process as these facts indicate, is by no means such a wild speculation as it might, from a priori considerations, have been supposed to be. 'Huxley noticed a lot of similarities between skeletons of things like pigeons and small meat-eating dinosaurs', Paul Barrett says. 'He proposed that birds and dinosaurs were very closely related, on the basis of things like the similar hollow spaces within the bones and similar bone structures in general.' The degree of similarity was such that one of the later specimens of Archaeopteryx, found in 1951, was initially mistaken for a young Compsognathus. Yale University's OC Marsh (see chapter 3) would endorse Huxley's ideas about bird origins when he described fossils of the early toothed birds Hesperornis and Ichthyornis in 1880. Despite this, the idea of birds evolving from dinosaurs didn't gain traction at this time, Barrett says. 'This whole debate just doesn't really take off, rather oddly. People are still busy describing fossils and just naming things and getting them out of the ground. The idea was never really taken up and then fell out of favour. Bit of a shame, because Huxley was dead on with most of the stuff.' The Berlin specimen and dinosaur death The next specimen of Archaeopteryx, found in 1877 in a quarry near Eichstätt – also in the Altmühl Valley – was a complete skeleton with a skull and its wings splayed out to the sides. The fossil, which ended up at the Naturkunde Museum in Berlin and came to be known as the 'Berlin specimen', is one of the most beautiful fossils ever collected. Nearly every delicate bone is visible, and it has a great fan of feathers marked in the limestone around the body and its long bony tail. 'The Berlin specimen is truly remarkable – and beautiful', John Ostrom wrote in a 1975 article for Discovery magazine: The skeleton is almost 100 per cent complete, with clear feather imprints and (unlike the London specimen) a very bird-like skull with teeth! The head and neck are arched back over the back: the long reptile-like tail is stretched out behind; the long bird-like legs are doubled back slightly; and the very long dinosaur-like arms and hands, with their great span of feathers, reach out on either side. The London specimen had been headless, but the Berlin specimen was replete with every detail. Owen had predicted that Archaeopteryx had a beak, like a bird, but just as Huxley had suggested, it also had a full set of tiny pointy teeth, much like its close relative Compsognathus. I've spent some time looking at the shape of the fossil and trying to imagine what this strange crow-sized bird might have looked like in life. As I pondered its shape, something began to perplex me: why was it twisted into such a strange position? If you've ever seen one of the Archaeopteryx fossils in a museum or even just a photo (see image section), you may have noticed the unusual shape of the body. All the known specimens display a typical 'death pose' also seen in many other dinosaurs fossils – the head and neck are awkwardly twisted back over the body and often the tail is recurved back to meet the head. 'Virtually all articulated specimens of Archaeopteryx are in this posture, exhibiting a classic pose of head thrown back, jaws open, back and tail reflexed backward, and limbs contracted', says Kevin Padian of the University of California, Berkeley. This position is known as opisthotonus (Greek for 'tightening behind'). The cause has been the topic of some debate since the 1920s: some experts thought it might be caused by water currents moving the neck after death, or that it was simply the result of rigor mortis or drying tendons. But in 2007, Padian and veterinarian-turned-palaeontologist Cynthia Faux, of the Museum of the Rockies in Bozeman, Montana, came up with an altogether different proposal. Faux told reporters that the traditional explanations made no sense to her: 'Palaeontologists aren't around sick and dying animals the way a veterinarian is ... [we] see this posture all the time in disease processes, in strychnine cases, in animals hit by a car or in some sort of extremis.' Read an Excerpt
Flying Dinosaurs
How Fearsome Reptiles Became Birds
By John Pickrell University of New South Wales Press Ltd
Copyright © 2014 John Pickrell
All rights reserved.
ISBN: 978-1-74224-682-6
CHAPTER 1
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Excerpted from Flying Dinosaurs by John Pickrell. Copyright © 2014 John Pickrell. Excerpted by permission of University of New South Wales Press Ltd.
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Dinosaurs aren't dead. Birds are dinosaurs, an astounding fact brought to life by John Pickrell in his celebration of fossil discovery. From historic debates over how birds evolved from dinosaurian ancestors to how this ancient connection is enlightening our understanding of dinosaur lives, Pickrell adeptly shows readers the Velociraptor hiding inside a chicken.
A marvelous book. The moment life took to the air—caught in stone!
Flying Dinosaurs recounts the stunning fossil discoveries, novel ideas, cutting-edge technologies, and scientific missteps that took place as scientists documented the dinosaur-bird link. In readable prose, with stunning illustrations and the necessary background material, this book recounts the cut-and-thrust of one of the most important paleontological advances of modern time.What People are Saying About This
Brian Switek
Table of Contents
Foreword, by Philip Currie
Preface
Introduction: A whole new world
Before we begin
1. The missing link
2. A feathered revolution begins
3. The dinosaur hunters
4. From dinosaur to bird
5. Fake fossils
6. The evolution of feathers
7. The struggle to the skies
8. Sex for T. rex
9. Colouring in the dinosaurs
10. Back from the dead
11. The survival game
Relationships of the theropod dinosaurs
An A–Z of feathered dinosaurs
References
Glossary
Select bibliography
Acknowledgments
Index
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