THE AGE OF REPTILES.

Star (Christchurch), Issue 16497, 6 August 1921, Page 15

THE AGE OF REPTILES.

WHEN THEY DOMINATED \ LAND, SEA AND AIR, 1 1 The history of life on the earth *®* ] Tealed by the fossils in the rooks, shows 1 that the animals appear in due order < according to their organisation (writes 1 ‘■hr W B. Dawkins in the “ Manchester i Guardian The simplest—the infinite ! variety of sponges, corals, molluscs, : etc., constituting the invertebrates— • appear in the oldest rocks, and the rest follow—the fishes, the newt tribe j (amphibia), the reptiles, the birds, the lower mammals (metatheria), and the higher mammals (eutheria) that have 1 been the masters of the earth from the < beginning of the tertiary period down to the present day. Man is the last in the long procession through ’ the • corridors of time.” The record in toe rocks, mostly consisting of banks ol sand and mud and other accumulations . in the seas and oceans, is most lm P® r ~ j feet but it is sufficient to prove that the order of the procession is the same over the whole earth. All this is well known to science, and can be studied in museums. It is, however a sealed ’ hook to the general puhlic that is, m ' my opinion, eager to learn, ana thankful for the .numbs that fall from the , geological table in the shape of notices , in the daily press. Sometimes these notices mislead the public, as, for ex, l ample, the alleged discovery at Enfield of “ some huge reptile ot the dim post ” more or less related to the American diplodocus In the superficial deposits which in that district y paleolithic and other later traces of • man. The reader is led to believe that - one of the great dinosaurian reptiles ' that disappeared from both the old and : the new worlds at the close of the sec- • endaTy period was living in Middlesex in comparatively modem times. It is, 1 however, unnecessary to criticise this • extraordinary geological anachronism, * liccause the remains in question belong, Dr Smith Woodward lias •already pointed out, to a horse, probably modern. The teeth show that it was old, and it may have been an old cab horse. Unfortunately it will take a very long time for the correction to catch up the ■ original mistake, if it ever does catch it up, as President Lincoln remarked of errors in political speeches. The names of the dinosaurs apparently fascinate the public. Only last year there was an announcement of ail American expedition into Central Africa to hunt the brontosaurus, which d’sappeared from the world at the end , of the oolitic period, but was supposed to survive in the tropical forests sa jet unexplored. It is clear from these iwo examples that tlio age of the leptiles is not yot part ot common know - 1 The age of reptiles is a period m the ancient history of the. earth infinitely ; remote as compared with the first appearance of man. It represents a stage f„ the evolution of life when reptiles *ero the dominant inhabitants of the earth and occupied the place now held by the mammalia in the economy of nature. They were masters of the land, ©f tho sea and even of tlio air. During the reptilian ago Britain was on the southern margin of a great continent, ranging from the highlands of Scotland to the north and west into *be Atlantic, and towards Sweden and Vorway and indefinitely towards the Pole The hills of the Lake district of TV ales Devon and Cornwall were islands end probable also the Pennines and the Mendips. On the ever-changing shoreline the banks of sand, mud and accumulations of shells and corals were dev posited that now form the secondary ceous—of Middle and South-eastern England. The continent and the islands were covered with forests, mostly of conifers, cveads and zamiao, with an undergrowth of ferns.

On this great continent, and its islande there were reptiles erreat and small some with naked scaly skins, and others covered with an armour oi ; bony platen and pointed horns. Some were of existing reptilian types, such as crocodileand gavials, while others (dinosaurs) are extinct. The latter, possessed or characters no longer found in the living reptiles, in size rivalled, if not surpassed, the largest elephants and giraffes. Dike the mammalia, thev consisted of eaters of plants and eaters of flesh. Among the former in Britain we may note the iguanadon of the Weald of Kent, a giant reptile living in tho forests, measuring l«3ft high, with feeth specially adapted for feeding on plants, and with a build and gait like a kangaroo. There is also the still larger cetiosaurus, 10$ft high and 60ft long, of tho oolitic strata of Oxford and Peterborough, which probably haunted the marshes, rivers and seashore, feeding mainly on aquatic plants, with its small, conical singularly inefficient teeth, and. like the diplolocua of America, heavy-footed and walking on all-fours. These creatures took the place in their world long afterwards occupied by the elephants, rhinoceroses, hippopotami and other herbivores in tho world of mammals. The most notable of tho flesh-eating dinosaurs—-the megaiosaurus—was specially. provided with double-edged and serrated cutting teeth of tho same design as those of tho sabre-toothed tiger of the middle and later tertiary strata and it Jived upon the reptilian herbi vores, just as the lions, tigers and wolves find their prey in the antelopes giraffes, deer, oxen and tho other living mammalia. We may take the above as examples of the large and varied land fauna of the groat secondary continent, found not only on ita margin in Britain, but also in Germay, Belgium and Trance. In the United States they are represented by analogous but more gigantic and more perfect forms that delight and astonish the European visitor to the museums of Yale, New York, Philadelphia and Washington. Some are so large that a dorsal vertebra placed on the floor of Dr Marsh’s laboratory at Yale raised its spine above my head, and was not less than stt Bin in height. The size of the reptile, with its backbone formed of many such vertebrae, may bo left to the imagination. In America, as in Europe, a great continent extended northwards through Canada and Greenland towards tho Pole, but it is an open question whether it was united with that of Europe in the secondary period. There is, however, no sign that land reptiles migrated from the one region to the other, and consequently there must have been a barrier to migration either of sea or climate. The reptiles were also the masters of the seas, lakes and rivers throughout the secondary period over the whole world, and present the same modifications of their reptilian characters for life in the water as are found in aquatic mammals. The fish lizard (ichthyosaurus) was an ooeangoer, like the whale, and was fitted for diving-to great depths. The pliosaurus and the plesiosaurus wore adapted for life in the shallows and for locomotion on land with their flippers, after the maimer of tho seal and walrus. The reptiles also were rulers of the air throughout tho whole of the secondary period, the pterodactyle taking the place of birds, and possessed of leathery wings like those of a bat. ft varied from a small size to a, creature with a stretch of wing of 29 feet. While, however, the reptilian mastery was undisputed in the secondary period, it must be noted that there were the beginnings of mammalian life on the land in small rnetathera (marsupials) and cf birds in the making, which have not yet lost their reptilian characters. The mastery of reptiles in nature was maintained down to the time when the great change® in geography took place, in the interval between, .the and tertiary periods.