Some Salient Points in the Science of the Earth

by Sir John William Dawson

[129] Journal of Geological Society of London, vol. ix.

[130] Journal of Geological Society, vol. x.; and additional notes, vol. xi.

The parts preserved in my specimen are the bones of the anterior and upper part of the skull in one fragment, and the teeth and palatal bones in others. These parts were carefully examined and described by Owen, and the details will be found in his papers referred to in the note. We may merely observe here that the form and arrangement of the bones showed batrachian affinities, that the surface of the cranium was sculptured in the manner of the group of Labyrinthodonts, and that the teeth possessed the peculiar and complicated plication of the ivory and enamel seen in creatures of this type. The whole of these characters are regarded as allying the animal with the great crocodilian frogs of the Trias of Europe, first known as Cheirotherians, owing to the remarkable hand-like impressions of their feet, and afterwards as Labyrinthodonts, from the beautifully complicated convolutions of the ivory of their teeth.

Unfortunately the original specimen exhibited only the head, and after much and frequent subsequent searching, the only other bones found are a scapula, or shoulder bone, and one of the surface scales which served for protection, and which indicate at least that the creature possessed walking limbs and was armed with bony scales sculptured in the same manner with the skull bones.

Of the general form and dimensions of Baphetes, the facts at present known do not enable us to say much. Its formidable teeth and strong maxillary bones show that it must have devoured animals of considerable size, probably the fishes whose remains are found with it, or the smaller reptiles of the coal. It must, in short, have been crocodilian, rather than frog-like, in its mode of life; but whether, like the Labyrinthodonts, it had strong limbs and a short body, or like the crocodiles, an elongated form and a powerful natatory tail, the remains do not decide. One of the limbs or a vertebra of the tail would settle this question, but neither has as yet been found. That there were large animals of the labyrinthodontal form in the coal period is proved by the footprints discovered by Dr. King in Pennsylvania, which may have been produced by an animal of the type of Baphetes, as well as by those of Sauropus unguifer from the Carboniferous of Nova Scotia, and which would very well suit an animal of this size and probable form. On the other hand, that there were large swimming reptiles seems established by the discovery of the vertebræ of Eosaurus Acadianus, at the Joggins, by Marsh.[131] The locomotion of Baphetes must have been vigorous and rapid, but it may have been effected both on land and in water, and either by feet or tail, or both. A jawbone found at the Joggins in Nova Scotia, and to which I have attached the name Baphetes minor, may have belonged to a second species. Great Batrachians allied to Baphetes, but different specifically or generically, have since been found in the coal formations of Great Britain, the continent of Europe and the United States.

[131] Silliman's Journal, 1859.

With the nature of the habitat of this formidable creature we are better acquainted. The area of the Albion Mines coal field was somewhat exceptional in its character. It seems to have been a bay or indentation in the Silurian land, separated from the remainder of the coal field by a high shingle beach, now a bed of conglomerate. Owing to this circumstance, while in the other portions of the Nova Scotia coal field the beds of coal are thin, and alternate with sandstones and shales, at the Albion Mines a vast thickness of almost unmixed vegetable matter has been deposited, constituting the "main seam" of thirty-eight feet thick, and the "deep seam," twenty-four feet thick, as well as still thicker beds of highly carbonaceous shale. But, though the area of the Albion coal measures was thus separated, and preserved from marine incursions, it must have been often submerged, and probably had connection with the sea, through rivers or channels cutting the enclosing beach. Hence beds of earthy matter occur in it, containing remains of large fishes. One of the most important of these is that known as the "Holing stone," a band of black highly carbonaceous shale, coaly matter, and clay ironstone, occurring in the main seam, about five feet below its roof, and varying in thickness from two inches to nearly two feet. It was from this band that the rubbish heap in which I found the skull of Baphetes planiceps was derived. It is a laminated bed, sometimes hard and containing much ironstone, in other places soft and shaly, but always black and carbonaceous, and often with layers of coarse coal, though with few fossil plants retaining their forms. It contains large round flat scales and flattened curved teeth, which I attribute to a fish of the genus Rhizodus, resembling, if not identical with, R. lancifer, Newberry. With these are double-pointed shark-like teeth, and long cylindrical spines of a species of Diplodus, which I have named D. acinaces.[132] There are also shells of the minute Spirorbis, so common in the coal measures of other parts of Nova Scotia, and abundance of fragments of coprolitic matter, or fossil excrement, sometimes containing bones and scales of fishes.

[132] "Supplement to Acadian Geology," pp. 43 and 50. These fishes are now known under the generic name Leptacanthus.

It is evident that the "Holing stone" indicates one of those periods in which the Albion coal area, or a large part of it, was under water, probably fresh or brackish, as there are no properly marine shells in this, or any of the other beds of this coal series. We may then imagine a large lake or lagune, loaded with trunks of trees and decaying vegetable matter, having in its shallow parts, and along its sides, dense brakes of Calamites, and forests of Sigillaria, Lepidodendron, and other trees of the period, extending far on every side as damp pestilential swamps. In such a habitat, uninviting to us, but no doubt suited to Baphetes, that creature crawled through swamps and thickets, wallowed in flats of black mud, or swam and dived in search of its finny prey. It was, in so far as we know, the monarch of these swamps, though there is, as already stated, evidence of the existence of similar creatures of this type quite as large in other parts of the Nova Scotia coal field. We must now notice a smaller animal belonging to the same family of Labyrinthodonts.