The Illustrated Encyclopedia of Pterosaurs [antikvár]

FOREWORD arth keeps From earlii é jeci ro tlie M'ilis of die anc Daedalus and lea menis of tlie tail E^ arth keeps a firm hold on its creatures. From earliest times, all life has been sub-J jeci ro the inescapable force of gravit It world like the legend of us', the early aircraft experi-of Ulm- or Otto Lilienthal^ show us how man has always dreamed of conquering these forces, of releasing himself from die pull of the Earth widi mechanical aids, and flying. In just the same way biological evolution did not come to a stop when confronted with air as a possible habitat: it conquered it in an astonishing number of ways. Two thirds of all species living today are capable of flight. The largest group are of course insects, by far the largest class widiin the animal kingdom, with more than three quarters of a million living species. The earliest representatives of flying insects in the history- of the Earth are known as fossils in Carboniferous strata about three hundred million years old. Apart from insects, only vertebrates, in the 1 Acajrcling to Greek legend Daedalus was an Adienian ardiiieci and sculptor, lie bulk an artificial labyrindi for the Minotaur for King Mino,s of Crete. Ii order to escape from captiviu- (jn Crete he made wings for liimself and liis .son Icams, using birds' feathers lield together with wax, Witli their help the rose into the air and flew ofF in the direction of hom De.spite his father's warning thai he should not fly to high, proud young Icarus soared up so far that the heat of the sun melted the wax in his wings plummelted into the sea, I lis unhappy fathc him dead on die shore of a nearby Island, c he buried him, and called tithe DxJecane,se Islands in tl 2 inlHllABerblinger.at; Danube at Ulm in a glider h attempt failed, 3 Otto Uliendial (1848-] 896J, an engine birds' flight and constructed gliders widi wings, in which he conducted flying experiments o\ distances of up to l.iXM (300m). In August 1896 he crashed in a monoplane glider, and was killed, Tlie Wright brothers laier t(K)k up this pioneer of llighfs experiments in America. Above: Hours of painstaking research are needed before a convincing portrait of tlie pterosaur as it appeared in life can be atiempted. Here the author is seen reconstructing die head of Plerodatisiro, tlie extraordinar}' 'flamingo pterosaur' from Argentina. and he which ;land Icaria. It is one of ; Aegean. lor, tried tolly over the had built him.self,The studied nibered shape of birds, bats and pterosaurs, have succeeded in penetrating the air as an 'ecological niche' by achieving active flight. All three groups solved the problem of overcoming gravity independently. Of these three groups it was the pterosaurs who were the first vertebrates to do this successfully, and that wjls over 200 million years ago, in the Triassic period, at the beginning of the Mesozoic Era, Flying makes extreme demands on the animal body, on skeleton and structure and on physiolog)', A flying animal is of course always r than air, but it must be as light as pos-jther hand its increased energ>' lands an appropriate re.spira-circulatory system and a high meta-, Complicated steering manoeuvres are only possible with suitably de- Left: Pterosaurs went extina abcM65 million years ago; it grjes without saying that no human being has ever seen a live pterosaur. We must, therefore, rely upon scientific study of their fossil remains lo form an impression of this fascinating group of animals, and to allow us to make informed deductions about their likely appearance and life st\ies. Despite the relative sc^dt\' of fossil evidence, palaeontologists have been able to build up quite a detailed piaureofa number of these'flying dragons' of primevd times. Some people have even been stimulated to make three-dimensional flying reconstruaions of pterosaurs, such as this model of Queizalcoailiis which is about to undergo a flight test. veloped nerve and brain structures. An abilit\' to fly actively does however offer enormous advantages: increased mobilirv' in the search for food and in avoiding enemies, flexibillt\' when living conditions are unfavourable, extension of territory' over a considerabl)' extended habitat. Despite differences in detail, ageneraily uniform body plan is to be found in all vertebrates capable of active flight. Obviously the only possible way in which tetrapods, or four-footed vertebrates, could fly was by their forelimbs o wings. So their flying organs absolutely free gift, they came at • loss of the forelegs. It is tempting to interpret early adaptations of reptiles to the medium of air as a first, oireful move towards accjuiring the abilit>' to fly, as in Daedalosaunis^ in die Permian, ovKuehneosau-ns' mid !carosanmJ' in tlie Triassic, These reptiles, die size of lizards, had flaps of skin bet^'een dieir elongated ribs, which allowed diem more or less passive downward gliding flight over a limited distance. A surviving example of diis principle of locomotion is die genus Draco , tlie so-called dragon of Soudi-Eiist Asia. In 1971 the Moscow zoologist A.G.Sharov discovered a hitherto unknown reptile in deposits from the late Triassic in Kirghizia (USSR), that he called Podopteiyx (leg-flier), and classified in the reptile order of pseudo- -i Cu-roll, R. L, 1978. ^ gM/J^ reptilefi-om tlx Upper I'ennim of Madagascar ftilaeontographica Africana. 21:143-159. 5 Robinson, RL, 1962. Gliding lizards/rom fix Upper Keiiper of Givat Britain. Proceedings of ihe Geologic-jl Society, London, 1601; 137-l-i6. 6 CoWKn. E.II. 1966-A gliding rvptile from tl.v Triassic of Netv Jersey- /\merican Mu,seum Novitates. 2246:1-23. 7 i-lying dragons of the genus Draco can sprad their rib wiiig.s and glide for a long distance from iree lo tree. To increase the gliding area the tail is also somewhat broiider at the base, and there aa- flaps of skin at the side t)f the chin, hi the case of Dnico gliding flights of up to 200ft (60m) iiavv been oixse[\'ed.