Popular Science Monthly/Volume 21/August 1882/A Gigantic Fossil Bird
|A GIGANTIC FOSSIL BIRD.|
THERE are really privileged persons within the scientific domain. M. Gaston Planté, whose name is associated with a most important advance in electrical knowledge, enjoyed the opportunity, in 1855, of making, in a wholly different direction, a discovery in paleontology that was of great interest. In a very curious bed of loam of the Eocene tertiary formation, called the ossiferous conglomerate of Men don, and which has now nearly disappeared, he found a bird's tibia, which measured, though it was not whole, forty-five centimetres in length. At first sight this great bone appeared to exhibit considerable analogies with the corresponding part of the swan, and differed from it only by the presence of the subtrochlean groove, and by the relatively high situation of the osseous arch, and the outer muscular attachment. But what a contrast in the size! An idea of it may be gained from Fig. 2, A and B, which represent the tibia of the Meudon bird to which Constant Prevost fittingly gave the name of Gastornis (Gaston's bird)—and the tibia of the common swan, on the same scale. After M. Plante's discovery, a geological formation corresponding exactly with the conglomerate of Meudon was found at Reims. Quite recently, Dr. Lemoine has established the connection between the beds of Reims and Mendon more closely by the discovery of the remains of gastornis in Champagne, from which he has constituted a new species that he calls Gastornis Eduardsii. The bird was not less than three Fig. 2.—A, Tibia of the Gastornis of Meudon (reduced to one third of the natural size). B, Tibia of the Common Swan (reduced to one third of the natural size). metres (about ten feet) high when standing, and is shown in that position in Fig. 1. The author possesses the femur, the tibia, the tarso-metatarsian, and several phalangeal bones of this bird. The pelvis is represented in his collection by an ischion and the upper extremity of the pubis. A cervical vertebra, a caudal vertebra, a fragment of the sternum, and ends of the ribs, have furnished him subjects for interesting observations. Dr. Lemoine has collected pieces of bone, which he considers half of a breastbone and a coracoid bone. He also describes the lower end of the humerus, a radius, a metacarpian, and the terminal phalangeal of the wing. A large proportion of the bones of the head have also been found by the author during his paleontological probings, and with their aid he is able to complete the description of this remarkable ornithological type.
All the parts of the skeleton so far discovered are represented in Fig. 1, where they have been so placed as to show the skeleton restored, in its normal position.
This richness of his material has enabled Dr. Lemoine to form very precise notions concerning the giant bird of the environs of Reims. In his opinion, the cranium must have been relatively voluminous and less disproportionate than the cranium of the ostrich.
This is indicated by the quadrate bone, a part of the orbitary cavity, and almost the whole of the base of the cranium, in which the occipital condyle, the sub-condylian furrow, the basilar tuberosities, the sphenoidal escutcheon, and the basipterygoid apophyses with their faces well accentuated, are exhibited. According to Mr. Huxley, this
character occurs now with several birds—divers, ducks, and hens—and with several lacertians and ophidians.
The upper mandible, which was found almost entire, is very remarkable for a series of false alveoles, reminding one of the atrophied alveoles of reptiles, and which probably corresponded, not with true teeth, but with thickenings of the horn of the bill. The bill also, toward its anterior third, seems to have represented a real tooth, but a tooth of a bony nature and of continuous substance with the bill itself. This mode of dentition had been previously observed by Richard Owen in the Odontopteryx toliapica.
The lower mandible is marked by its terminal extremity, which seems to have been slender, and by its hinder half presenting faintly-accentuated muscular attachments.
A part of the sternum does not permit us to say whether that portion of the skeleton had a keel. The shoulder seems to have been composed of a quite short breast-bone with a wide posterior articular surface, of a coracoid bone and of a scapulum, the group isolated and quite different from the single bone of the ostrich. The humerus is, like all the other bones of the wing, more voluminous than in the ostrich. The cubitus rather recalls the shape of that bone in ordinary birds, and bears marks indicatory of feathers. The radius was thin, the metacarpians appear to have been independent, offering a characteristic of great value, for it occurs only in two other orders. The iliac bone, very distinct, is remarkable for the sloping character of its posterior border. It is very difficult in the face of such characteristics to fix the true affinities of the gastornis. MM. Hebert, Ed. Lartet, and R. Owen, have expressed opinions on this point, and the latter is inclined to refer the fossil bird to the order of the waders, and more especially to the rails. M. Alphonse Milne-Edwards is of a different opinion, and is rather disposed, on the ground of a variety of osteological traits, to classify the gastornis with the ducks. But he is prompt to recognize that the Eocene animal offers peculiarities so different from anything shown in living nature that it is impossible to place the gastornis in any of the established natural groups. Another gastornis has been found at Reims, which Dr. Lemoine has described under the name of Gastornis minor; and the author has besides found the remains of two entirely different genera of birds.—Translated from La Nature.