Pterosaur

“ In the course of time they lose the teeth—an advantage in the distribution of the weight of the body while flying—and develop horny beaks. In the gradual shaping of the breast-bone and head, also, they illustrate the evolution of the bird-form.
But the birds were meantime developing from a quite different stock, and would replace the Pterosaurs at the first change in the environment. There is ground for thinking that these flying reptiles were warm-blooded like the birds. ”

“ The Pterosaurs are wholly Mesozoic, ranging from the Lias to the Chalk inclusive; and the fine-grained Lithographic Slate of Solenhofen has proved to be singularly rich in their remains. The genus Pterodactylus itself has the jaws toothed to the extremities with equal-sized conical teeth, and its species range from the Middle Oolites to the Cretaceous series, in connection with which they will be again noticed, together with the toothless genus Pteranodon. ”

“ But even then there are undoubtedly Dinosaurs belonging to that period, so that the question of relationship would resolve itself into a common origin, not a derivation of birds from Dinosaurs." Of the relation between birds and Pterosaurians, particularly Pterodactyles—and Prof. Newton has conclusively shown most interesting resemblances — Mr. Beddard considers the main difficulty "in the way of comparing Pterodacytles and birds is in the fact that both can fly, and that each has acquired the power of flight by a different method. ”

“ The flying Reptiles or Pterosaurians, partly took the place of birds, and most of them were of small size. Strange bat-winged creatures, the wing membrane stretched on the enormously elongated fourth finger, they are of all extinct reptiles the least understood, the most difficult to reconstruct and visualize as they were in life. ”

“ It is as if, in flying experiments, a man were to have a web of silk stretching from his arm and an extension of his little finger to the side of his body.
From the small early specimens in the early Jurassic the flying reptiles grow larger and larger until the time of their extinction in the stresses of the Chalk upheaval. Small Pterosaurs continue throughout the period, but from these bat-like creatures we rise until we come to such dragons as the American Pteranodon, with a stretch of twenty-two feet between its extended wings and jaws about four feet long. ”

“ Here again paleontology is not merely an auxiliary to zoology; it is chief of a division and enjoys certain unique advantages. We pass in review with the pedigrees and the prodigies of fitness, the entirely unreasonable, irrational, paradoxical extremes of structure, such, for example, as the pterosaurs, which far surpass in boldness and ingenuity of design any of the creations of the modern yacht builder which are mistakenly regarded by some as having reached an absurd extreme. ”

“ Such structures must be light and therefore delicate, and yet possess very considerable strength to resist the strain of the body’s prolonged sustentation, and to effect its occasionally very rapid progress, as in the swift and in dragon-flies. These conditions which we find fulfilled in all existing flying organisms were also fulfilled organisms which have for ages passed away from the surface of this by planet, such as the extinct flying reptiles called Pterosauria or Pterodactyles. ”

“ Or does it not with Dicynodonts and Dinosaurs rather form an outlying class uniting the reptiles with the mammals.
In the same way, when Pterosauria and Dinosauria are placed above living reptiles, we are compelled to ask how much are they above, or what are the characters which bind them to the Reptilia at all? No satisfactory evidence has ever been adduced to show that the Dinosauria are Reptiles. ”

“ Only rarely does it occur as an ossification in other reptiles, the best examples of which are the Pterosauria (Fig. 94 e) where, as a broad, shallow concave bone, it covers the whole under side of the thoracic region with a stout manubrium-like process in front, but without a true keel. ”

“ Throughout the whole series of the mesozoic rocks we meet with some exceedingly remarkable flying creatures, some of which attain a great size, their wings having a span of eighteen or twenty feet or more, and these are known as Pterosauria, or Pterodactyls. ”

“ Sometimes the postorbital bar is incomplete in lizards (Fig. 56) , snakes (Fig. 59) , and therapsids (Fig. 45 d) . The prefrontal is excluded in some dinosaurs, the postorbital in Araeoscelis (Fig. 52) and Hyperodapedon (Fig. 62 d) , leaving not a single element invariably associated with the orbit. Antorbital or preorbital vacuities are very characteristic of the Archosauria, occurring in all phytosaurs (Figs. 66 b, 67 a) and true pseudosuchians (Fig. 65 b, d) , most Saurischia (Fig. 70 a, b) and Pterosauria (Fig. 71) and some Crocodilia. ”

“ Before we leave the group of reptiles we may glance at the very strangely modified skull of Pteranodon, one of the extinct flying reptiles, or Pterosauria. In this very curious skull the region of the jaws, or beak, is greatly elongated and pointed; the occipital bone is drawn out into an enormous backwardly-directed crest; the posterior part of the lower jaw is similarly produced backwards; the orbit is small; and the
Fig. ”

“ Among the mammalia and birds there are none extinct; but when we come to the reptiles there is a most wonderful thing: out of the eight orders, or thereabouts, which you can make among reptiles, one-half are extinct. These diagrams of the plesiosaurus, the ichthyosaurus, the pterodactyle, give you a notion of some of these extinct reptiles. And here is a cast of the pterodactyle and bones of the ichthyosaurus and the plesiosaurus, just as fresh as if it had been recently dug up in a churchyard. Thus, in the reptile class, there are no less than half of the orders which are absolutely extinct. ”

“ A Monstrous Dinosaur.—Assistant-Professor W.H. Reed, of the Geological University of Wyoming, has made a great discovery by unearthing the petrified bones of the most colossal animal ever taken from the earth's crust. This fossil monster was a dweller in the Jurassic age, a Dinosaur, measuring nearly 130 ft. in length, and being perhaps 35 ft. in height at the hips and 25 ft. at the shoulders—an animal so terrible in size that its petrified skeleton alone is believed to weigh more than 40,000 pounds. ”

“ One special development of the dinosaurian type of reptile was a light, hopping, climbing group of creatures which developed a bat-like web between the fifth finger and the side of the body, which was used in gliding from tree to tree after the fashion of the flying squirrels. These bat-lizards were the Pterodactyls. They are often described as flying reptiles, and pictures are drawn of Mesozoic scenery in which they are seen soaring and swooping about. But their breastbone has no keel such as the breastbone of a bird has for the attachment of muscles strong enough for long-sustained flying. ”

“ It seems natural to pass from the fossil reptiles to the birds. But as a matter of fact the birds are not very closely related to the Pterodactyls, and seem to have been descended from some other very special form of reptiles, so peculiar as to be considered a distinct class. It may actually have been descended from those reptiles among the Dinosaurs which walked on their hind legs and had only three toes to the foot. The first bird found belongs to Jurassic times; and its skeleton, found in some slate remains at Solenhofen in Bavaria, is now to be seen in the Natural History Museum. ”

“ For I imagine, if it can be determined what the nervous and respiratory and circulatory structures of the Pterodactyle were, it becomes a secondary matter to know whether the phalanges are like a lizard's, or the pelvis like that of a mammal. If the animal is asserted to be a mammal, a reptile, or a bird, we ought to be able to adduce evidence that it had the soft parts which are deemed distinctive of the selected class. ”

“ Land reptiles abounded, including species of the pterodactyle of the preceding age—tortoises, trionyces, crocodilians—and the pliosaurus, a creature which appears to have formed a link between the plesiosaurus and the crocodile. We know of at least six species of the flying saurian, the pterodactyle, in this formation.
Now, for the first time, we find remains of insects, an order of animals not well calculated for fossil preservation, and which are therefore amongst the rarest of the animal tribes found in rocks, though they are the most numerous of all living families. ”

“ The Dinosaurs, like Pterodactyles, must be regarded as intermediate in some respects between Reptiles and Birds. The resemblances enumerated would alone constitute a partial transition from the Reptile to the Bird, although no Dinosaurs have organs of flight; many are heavily armoured with plates of bone, and few, if any, approximate in the technical parts of the skeleton to the Bird class, except in the hind limbs. Yet Dinosaurs have sometimes been regarded as standing to Birds in the relation of ancestors, or as parallel to an ancestral stock. ”

“ The immense interval of time that preceded, and the no less vast stretch of time that separated them, is represented in the record of Dinosaur history by a multitude of tracks and a few imperfect skeletons assigned to the close of the Triassic period, and by a few fragments from formations which may be [24] intermediate in age between the Jurassic-Comanchic and the late Cretacic. Consequently we cannot expect to trace among the Dinosaurs, the gradual evolution of different races, as we can do among the quadrupeds of the Age of Mammals. ”

“ The first of the armored plant-eating dinosaurs, Stegosaurus, inhabited the dry plains. There were also some smaller, kangaroo-size plant-eaters that were two-footed.
A wide variety of dinosaur fossils has been found in the rocks of the Cretaceous Period, the last of the Mesozoic Era. The huge swamp dwellers still thrived. The flesh-eaters had evolved much larger types and included 40-foot Tyrannosaurus, the largest that ever lived. All the flesh-eaters walked on their hind legs as did their predecessors of the Jurassic and Triassic Periods. ”

“ Dinosaurs, which were contemporary with Ornithosaurs, approximate to them in blending characters of Birds with the structure of a Reptile and something of a Mammal in one animal. If an Ornithosaur is Reptilian in its backbone, in the articular ends of each vertebra having the cup in front and ball behind in the manner of Crocodiles, Serpents, and many Lizards, a Dinosaur like Iguanodon, which had the reversed condition of ball in front and cup behind in its early vertebræ, may be more Mammalian than Avian in a corresponding resemblance of the bones to the neck in hoofed Mammals. ”

“ Actually the dinosaurs show as much diversity in size, body form, and habits as any group of reptiles. The smallest dinosaur walked on its 2 hind legs like a chicken 4 and was about the same size. The largest walked on all 4 legs, was about 80 feet long, and weighed 30 to 40 tons. As examples of variety in body form there are the two-footed, flesh-eating Antrodemus, the armored Stegosaurus, the turtle-like Ankylosaurus, the horned Triceratops, the huge Apatosaurus, the two-footed vegetarian Camptosaurus, and the great variety of head forms in the aquatic hadrosaurs. ”

“ Mesozoic reptiles are of special interest and significance not only in themselves, but also because from one of their branches the birds were evolved, and from another the mammals. “In advancing from the amphibian to the reptile the evolution of the Vertebrates was far from finished. The cold-blooded, clumsy and sluggish, small-brained and unintelligent reptile is as far inferior to the higher mammals, whose day was still to come, as it is superior to the amphibian and the fish.” ”

“ HERE were in the sea in very ancient times—long before the flood—two very large and wonderful reptiles. Of them we present striking illustrations. One of them has been named the Ichthyosaurus, which means Fish Reptile. Its head somewhat resembled that of the crocodile, except that the orbit was much larger, and had the nostril placed close to it, as in the whale, and not near the end of the snout. It had four paddles and a powerful tail, and was very active in its movements and a rapid swimmer.
The other huge reptile was the Plesiosaurus, the meaning of which is “Near to a Reptile.” ”

“ It is the first flash of light on a dark problem, and its brilliance of inference has never been equalled. Its effects were seen when Prince Charles Bonaparte, the eminent ornithologist, in Italy, suggested for the group the name Ornithosauria; when the profound anatomist de Blainville, in France, placed the short-tailed animal in a class between Reptiles and Birds named Pterodactylia; and Andreas Wagner, of Munich, who had more Pterodactyles to judge from [Pg 31] than his predecessors, saw in the fossil animal a saurian in transition to a bird. ”

“ When we consider that almost the only vertebrata of this period were huge Saurian reptiles like the Icthyosaurus, Plesiosaurus, and Dinosaurus, with the flying Pterodactyles; and that the great mass of our existing genera, and even families, of fish and reptiles had almost certainly not come into existence, we see at once that types of insect-form are, proportionately, far more ancient. At this remote epoch we find the chief family types (the genera of the time of Linnæus) perfectly differentiated and recognisable. ”