Thomas Henry Huxley

“ Examining for this purpose the humeral extremity of the bone, and collecting all the examples, I found it was composed of two elements ossified together, these elements concurring on one edge to form an articular cavity. Of these elements the broader and shorter one, which extended toward the sternum, was coracoidian in form, and perforated in each of four specimens. If, as appeared now to be the case, this was the coracoid, surely the great heavy bone so long called by that name was a pelvic bone, and the restoration of the skeleton must proceed on an entirely new basis. ”

“ If the strongly crested sternum and the acute angulation of the union of the scapula and coracoid were marks of ornithic affinity, they would be found in all birds. The contrary is true: they are found only in those birds which fly; and the crest exists in bats, which cannot be said to have any affinity with birds.
On the other hand, the peculiarities of the hind limb and pelvis which the Ornithoscelida share with birds are found in all birds. ”

“ The Trias of North America has yielded the remains of two forms of reptiles, Clepsysaurus and Bathygnathus [12] . The teeth, jaw-fragments, and vertebræ of these reptiles have characters which are quite in accordance with those of the Dinosauria, to which group they have lately been referred by Cope and Leidy, and I entertain no doubt that they are Dinosauria; but, unfortunately, none of the remains which have been discovered belong to what may be called diagnostic bones, such as the ilium, the femur, or the tibia. ”

“ It is the bone which has been called 'clavicle' in Megalosaurus and Iguanodon by Cuvier and his successors, though the sagacious Buckland had hinted its real nature [6] . But these bones are not in the least like the clavicles of any known animal, while they are extremely similar to the ischia of such a bird as an ostrich; and in the only instance in which they have been found in tolerably undisturbed relation with other parts of the skeleton, namely, in the Maidstone Iguanodon, they lie, one upon each side of the body, close to the ilia. ”

“ The determination of the structure of the shoulder-girdle threw open the homology of this bone, which clearly could not be a clavicle, whatever else it might be. The alternative position once more lay in the pelvis, and this time between the ischium and the pubis; and as the ilium was bird-like, might not the ischium, or pubis, be also expected to be ornithic in form? At any rate the bone answered remarkably well to the ischium of one of the Ratitæ.
Resemblances to the structures found in some birds had already been noted by Prof. Owen [1] in the sacrum of the Dinosauria ”

“ In Iguanodon it has the obturator process characteristic of the same bone in Birds; and I imagine that the same process is seen in Compsognathus. In Hypsilophodon there can be no mistake about the matter, and the remarkable slenderness and prolongation of the ischium gives it a wonderfully ornithic character. In Iguanodon this slenderness and prolongation are carried beyond what is to be seen in Birds. I am disposed to think, however, that, as was certainly the case in Hypsilophodon, the ischia united in a median ventral symphysis in all the Dinosauria. ”

“ Considering that three sets of Thecodontosaurian teeth have been found for only a solitary Palæosaurian tooth, the probabilities would seem to be in favour of the bones belonging to Thecodontosaurus. But, on the other hand, the teeth of Thecodontosaurus are Scelidosaurian in character; and it seems to be hardly likely that these teeth should have accompanied hind limbs which are the reverse of Scelidosaurian, and exaggerate the peculiarities of those of Megalosaurus, when we have, in Palæosaurus, a tooth so like that of Megalosaurus that it is only distinguishable by critical examination. ”

“ I suspect that the ilium is broken in the middle, and, as a consequence, that the distance from the posterior to the anterior ends of the visible parts of the bone (6⋅6 inch) is somewhat greater than it should be. Hence the acetabulum probably appears to be longer than it naturally is. The postacetabular process (c) , which should articulate with the ischium, is swollen and thick, but thins off, above and behind, into a thin vertical plate, the posterior curved margin of which is broad and turned in, like a narrow shelf. ”

“ The posterior edge of the bone is concave and free. Posteriorly and below, it ends in a broad thin prolongation, which passes backwards, internal to the ischium. The part of the bone which bears the facet answers very well to the præacetabular process of the ilium of Megalosaurus and of Thecodontosaurus. The perforation is indeed somewhat like that which is so generally found in the pubis of Lizards; but, on a future occasion, I hope to be able to show its analogue in the ilium of an undoubted Dinosaurian. ”

“ When the posterior edges of the condyles of the tibia rest upon a flat surface, the one flat surface of the distal end of the bone looks outwards as well as forwards, and the other inwards as well as backwards, and the axis of the distal end is inclined at an angle of 45° to the flat surface from within and in front, backwards and outwards, thus exactly reversing the direction in the Reptile. ”

“ E. D. Cope pointed out the anomalous relations existing between the tibia and the fibula in certain of the Dinosauria, as illustrated by the genus Lælaps. He remarked, the distal extremity of the tibia is transverse and much compressed, and does not exhibit any of the usual appearances of an articular surface, neither the reptilian condyle, nor a cotyloid cavity sufficient for an astragalus of the size necessary for an animal of such bulk. A bone presenting a broad hour-glass-faced articular surface was discovered with the other remains, and had puzzled the anatomists who had seen it. ”

“ When the Stonesfield fossils came before me for lectures to a practical class, it was often my desire to present a sketch of the skeleton for comparison with that of a crocodile, and a pleasure to me to employ in this way such knowledge of the osteology of reptiles as a few dissections, now thirty or forty years ago, of each great reptilian group had fixed in my mind. ”

“ The teeth do not become worn by mastication.
2. The anterior prolongation of the ilium is nearly as large as, or larger than, the posterior.
3. The rami of the mandible are deep and thick and meet by rounded ends in the symphysis.
4. The proximal end of the femur is flattened, curved, and twisted in such a manner that its plane is oblique to that of a flat surface on which the condyles rest. In other words, it is more or less crocodilian.
5. There is no dermal armour.
Teratosaurus, Palæosaurus, Megalosaurus, Poikilopleuron, Lælaps, and probably Euskelosaurus belong to this group. ”

“ Every character which is here added to Von Meyer's diagnosis and description of his Pachypoda has failed to stand the test of critical investigation; while it is to birds and not to mammals that the Dinosauria approach so closely. There is, in fact, not a single specially mammalian feature in their whole organization. ”

“ In the extreme east of Europe, namely in the Ural Mountains, there is a series of rocks which have been supposed to be Permian, but which there now appears to be every reason to consider to be of Triassic age. Remains of reptiles associated with those of Labyrinthodonts from these rocks have been described and figured by D'Eichwald ('Lethæa Rossica') and by Von Meyer (Palæontographica, Bd. xv.) . Now the teeth and jaws of the Deuterosaurus of D'Eichwald, no less than the vertebræ which are referred to the same genus by this author, have a strongly Dinosaurian aspect ”

“ It seems to me that these three bones were all that were in the metatarsus, and that the creature was tridactyle; but of course there may be reason not to trust too much to one case for proof of a negative. Still that seems to me the probable inference. As we have plenty of information about the femur, tibia (fibula?) , metatarsals, and claw-bone, the reconstruction of the animal seems now practicable. ”

“ Owen (p. 2) . He terms the femur (65) "the right femur," and states that "the bones of the right hind leg are almost completed when the blocks containing their opposite ends are brought into juxtaposition." But the most cursory inspection is sufficient to show that the femur belongs to the left side, and, as I have proved, the so-called right tibia and fibula (66 and 67) are really the two ischia and the pubes.
I find myself compelled to dissent as widely from Prof. Owen's view of what he terms "the principal bones of the right hind foot." I have no sort of doubt it is the left hind foot. ”

“ The Dinosauria, a group of extinct reptiles, containing the genera Iguanodon, Hadrosaurus, Megalosaurus, Poikilopleuron, Scelidosaurus, Plateosaurus, &c., which occur throughout the whole series of the Mesozoic rocks, and are for the most part of gigantic size, appear to me to furnish the required conditions. ”

“ In the Crocodiles, the inner extremities of the pubes remain cartilaginous for a great extent, and consequently the ossified parts of the pubes remain widely apart in the dry skeleton.
Prof. Phillips has shown me what I believe to be fragments of the pubes of Megalosaurus in the Oxford Museum. If the determination is correct, they resembled those of the Ostrich in many respects. As they are detached, there is no certainty respecting their direction. The pubes of Compsognathus are, unfortunately, obscured by the femora. They seem to have been very slender ”

“ The bones referred to and described by Riley and Stutchbury are vertebræ, ribs of two kinds, a clavicle, two "coracoids," a humerus, a "radius," two femora, an "ischium," a tibia, a fibula, metacarpal and metatarsal bones, and ungual phalanges.
The "coracoid" figured is, as I suspected, a fragmentary ilium. The "radius" I take to be a tibia. The parts of the skeleton which diagnose the Dinosaurian nature of these reptiles, in addition to the teeth, are:—1, a caudal vertebra with the chevron bone; 2, an ilium; 3, a tibia. ”

“ The vertebral column of the specimen in the British Museum has been particularly described by Professor Owen; but the caudal vertebræ have been much more completely cleared of the matrix since his memoir was written. The remains of eighteen vertebræ may be made out, in consecutive series, from the cervical to the posterior dorsal region; and the position of the ilium is such, that there can hardly have been more than two or three vertebræ between the hindermost of those which are visible and the sacrum. ”

“ In fact, Plieninger's figures, (which do not quite deserve the reproaches with which Von Meyer visits them) prove that the skeletons A & B belong to Dinosauria. But they also seem to me to show that one or two of Plieninger's determinations are erroneous. Thus, the two vertebræ of B, represented in tab. xii. fig. 14, are certainly cervical. The bone called "ischium" (tab. xii. fig. 5) is the united scapula and coracoid, having a characteristically Dinosaurian form. On the other hand, the so-called "scapula" (tab. x. fig. 7) looks to me very much like the ischium ”

“ And, in conclusion, I may draw attention once more to the very remarkable fact, that, so far as the present evidence goes, the dry land of those Triassic epochs was as extensive in the old and northern New World as it is at the present day, and that, just as the mammalian and ornithic faunæ of these regions lead us to group North America, Europe, Asia, and South Africa in one vast Arctogæal province, so the affinities of the land reptiles of the Trias lead to the conclusion that at that epoch the same regions constituted a similar great distributional area. ”

“ From the coronoid process, the height diminishes with a tolerably rapid sweep (but not so rapid as in Iguanodon) , and the broken end, 2⋅5 inches from the articular surface, is only 0⋅5 inch high. The mandibular teeth are completely hidden.
The centrum of a vertebra (fig. 1, c) , which lies on the outer side of the ramus of the mandible, is 0⋅6 inch long, and the exposed articular end, which is very slightly concave, is 0⋅45 inch high by 0⋅4 inch wide. ”

“ The very remarkable reptile, Compsognathus longipes, has many affinities with the Megalosauridæ, Scelidosauridæ, and Iguanodontidæ, but it presents, at the same time, so many differences from all these, and so much of its structure is left unrevealed by the solitary specimen which exists, that perhaps the most convenient course which can be adopted, at present, is to make it the re- presentative of a group equivalent to them. ”

“ All the long bones are hollow. Portions of at least eight individuals have been found in the same bed.
Mr. Seeley doubted whether these animals should be called Reptiles at all, as they seemed to him to form a group distinct alike from reptiles, birds, and mammals, but occupying an intermediate position. In the hinder limbs of Pterodactylus the analogies were closer with mammals than with birds. He thought it possible that the peculiar structure of the hinder limbs of the Dinosauria was due to the functions they performed rather than to any actual affinity with birds. ”

“ The ilia are prolonged forwards, in front of the acetabulum, as well as behind it; and the resemblance to the bird's ilium thus produced is greatly increased by the widely arched form of the acetabular margin of the bone, and the extensive perforation of the floor of the actabulum. ”

“ It may be said that all birds stand upon their hinder feet, and that, as the Ornithoscelida did the same, the resemblance of structure arises from a resemblance of function. But I doubt if the majority of the Dinosauria stood more habitually upon their hind limbs than Kangaroos or Jerboas do ”