The invention of dinosaurs

Fourteen years younger than Mantell, Richard Owen also studied medicine, but concentrated in particular on anatomy. He gained a reputation as a skilled anatomist, and acquired a position at the Royal College of Surgeons in London, which gave him access to a great deal of comparative material and, through considerable industry and skill, allowed him to foster a reputation as the 'English Cuvier'. During the late 1830s, he was able to persuade the British Association to grant him money to prepare a detailed review of all

8. Photograph and sketch of 'Mantel-piece', a partial skeleton discovered in Maidstone, Kent, in 1834

9. Mantell's sketch reconstructing Iguanodon (c. 1834)

that was then known of British fossil reptiles. This eventually resulted in the publication of a stream of large, well-illustrated volumes that would mimic the hugely important works (notably the multi-volume Ossemens Fossiles) published by Cuvier earlier in the century, and further cemented Owen's scientific reputation.

This project resulted in two important publications: one in 1840 on mostly marine fossils (Conybeare's Enaliosauria) and another in 1842 on the remainder, including Mantell's Iguanodon. The 1842 report is a remarkable document because of Owen's invention of the new 'tribe or sub-order ... which I ... name ... Dinosauria'. Owen identified three dinosaurs in this report: Iguanodon and Hylaeosaurus, both discovered in the Weald and named by Mantell; and Megalosaurus, the giant reptile from Oxford.

He recognized dinosaurs as members of a unique and hitherto 0

unrecognized group on the basis of several detailed and distinctive | anatomical observations. These included the enlarged sacrum j

(a remarkably strong attachment of the hips to the spinal column), 1 the double-headed ribs in the chest region, and the pillar-like t construction of the legs (see Figure 10). e

In reviewing each dinosaur in turn, Owen trimmed their dimensions considerably, suggesting that they were large, but in the

10. Owen's reconstruction of Megalosaurus (c. 1854)

region of 9 to 12 metres, rather than the more dramatic lengths suggested by Cuvier, Mantell, and Buckland on previous occasions. Furthermore, Owen speculated a little more on the anatomy and biology of these animals in words that have an extraordinary resonance in the light of today's interpretations of the biology and way of life of dinosaurs.

Among his concluding remarks in the report, he observed that dinosaurs:

attained the greatest bulk, and must have played the most conspicuous parts, in their respective characters as devourers of animals and feeders upon vegetables, that this earth has ever witnessed in oviparous [egg-laying] and cold-blooded creatures.

And also that:

The Dinosaurs having the same thoracic structure as the Crocodile, may be concluded to have possessed a four-chambered heart . . . more nearly approaching that which now characterizes the warmblooded Mammalia.

Owen's conception was therefore one of very stout, but egg-laying and scaly (because they were still reptiles) creatures resembling the largest mammals to be found in the tropical regions of the Earth today; his dinosaurs were in effect the crowning glory of a time on Earth when egg-laying and scaly-skinned reptiles reigned supreme. Owen's dinosaurs were the ancient world's equivalents of present-day elephants, rhinos, and hippos. Looked at purely from the logic of scientific deduction, based on such meagre remains, this was not only brilliantly incisive, but an altogether revolutionary vision of creatures from the ancient past. Such breathtaking vision is all the more remarkable when it is juxtaposed to the 'gigantic lizard' models, though these were entirely reasonable and logical interpretations built on established and respected Cuvierian principles of comparative anatomy.

The creation of the Dinosauria had other important purposes at the time. The reports also offered a sweeping refutation of the general progressionist and transmutationist movements within the fields of biology and geology during the first half of the 19th century. Progressionists noted that the fossil record seemed to show that life had become progressively more complex: the earliest rocks showed the simplest forms of life, while more recent rocks showed evidence of more complex creatures. Transmutationists noted that members of one species were not identical and pondered whether this variability might also allow species to change over time. Jean Baptiste de Lamarck, a colleague of Cuvier in Paris, had suggested that animal species might transmute, or change, in form over time o through the inheritance of acquired characteristics. These ideas 0 challenged the widely held, biblically inspired belief that God had | created all creatures on Earth, and were being widely and j acrimoniously discussed. 1

Dinosaurs, and indeed several of the groups of organisms S

recognized in the God-fearing Owen's reports, provided evidence that life on Earth did not demonstrate an increase in complexity over time - in fact quite the reverse. Dinosaurs were anatomically reptiles (that is to say, members of the general group of egg-laying, cold-blooded, scaly vertebrates); however, the reptiles living today were a degenerate group of creatures when compared to Owen's magnificent dinosaurs that had lived during Mesozoic times. In short, Owen was attempting to strangle the radical, scientifically driven intellectualism of the time in order to re-establish an understanding of the diversity of life that had its basis closer to the views espoused by Reverend William Paley in his book entitled Natural Theology in which God held centre-stage as the Creator and Architect of all Nature's creatures.

Owen's fame grew steadily through the 1840s and 1850s, and he became involved in the committees associated with the planning of the relocated Great Exhibition of 1854. It is a curious fact that Owen, for all his burgeoning fame, was not first choice as the scientific director for the construction of the dinosaurs - Gideon Mantell was. Mantell refused on the grounds of persistent ill-health, and also because he was exceedingly wary of the risks associated with popularizing scientific work, particularly the risk of misrepresentating imperfectly developed ideas.

Mantell's story ended in tragedy: his obsession with fossils and the development of a personal museum led to the collapse of his medical practice, and his family disintegrated (his wife left him and his surviving children emigrated once they were old enough to leave home). The diary that he kept for much of his life makes melancholy reading; in his final years he was left lonely and racked by chronic back pain, and he died of a self-administered overdose of

M laudanum.

re g

£ Although outflanked by the ambitious, brilliant, and crucially full-time, scientist Owen, Mantell spent much of the last decade of his life continuing research on 'his' Iguanodon. He produced a series of scientific articles and extremely popular books summarizing many of his new discoveries, and he was the first to realize (in 1851) that Owen's vision of the dinosaurs (or at least Iguanodon) as stout 'elephantine reptiles' was probably wrong. Further discoveries ofjaws with teeth, and further analysis of the partial skeleton (the 'Mantel-piece'), revealed that Iguanodon had strong back legs and smaller, weaker front limbs. As a result, he concluded that its posture may have had much more in common with the 'upright' reconstructions of giant ground sloths (paradoxically inspired by Owen's detailed description of the fossil ground sloth Mylodon). Unfortunately, this work was overlooked, largely because of the excitement and publicity surrounding Owen's Crystal Palace dinosaur models. The truth of Mantell's suspicions, and the strength of his own intellect, were not to be revealed for a further 30 years, and through another amazing piece of serendipity.

+1 0

Post a comment