Great Roof

Wherein Charles H. Sternberg describes the discovery and the characteristics of a large marine turtle called Protostega gigas ("first Great roof"). There is some confusion over the locality given by Sternberg in this article (Plum Creek in Gove County) which was later repeated by Wieland (1906). The error was corrected by Sternberg in his 1909 book, The Life of a Fossil Hunter.

THE FIRST GREAT ROOF
BY CHAS. H. STERNBERG.

Professor Cope, from his own fertile brain, created the genus Protostega, and described the type species gigas, from the material he dug with such infinite care [?!?!] and patience from the chalk of Butte Creek, Logan Co., Kansas, in 1871, and in his laboratory with his own hands put together the broken fragments of the friable bones (a task of patient endurance few men are capable of). He showed his intense interest in the greatest of all sea tortoises. I doubt not that as he restored the fragile bones piece by piece, and they began to grow under his skillful hands, he was carried away with the idea of so many paleontologists of that time, and of many to this day, namely, that from a few bones of the skeleton he could restore the whole structure as it appeared in life.

      The broken dislocated ribs seemed to carry out his preconceived idea, that our living forms have been derived from ancestors (in past geological ages), that partook of the characters of immature living forms. In other works, he had before him a fully grown gigantic turtle, built on the same lines as those of a young turtle, just hatched from the shell, with bones all distinct. But here a great obstacle had to be surmounted, for from the manner of deposition, he concluded that the tortoise was buried on his back. What could he do with the great plates of bone, four in number, that lay below the ribs? It never seemed to occur to him that these were bones of the plastron, and in order to describe it bottom side up, he put them in the skin of the back as “lateral dermal plates.”
     The ossified neural arches, of which he found fragments, he made into central “dorsal shields.” Very likely the roof of the great Mormon Tabernacle at Salt Lake rose before him, and, behold, Protostega gigas, “the first great roof” was created.
     For 23 years I have firmly believed that these ideas were correct, and nothing was more deeply impressed on my mind than his story of “The Boatman of the Cretaceous Ocean.” I have found many fine specimens since 1875 (when I first began collecting in the Kansas chalk). But the bones were always scattered, as in the type, and I saw, or read nothing to cause me to change my mind. I have now, for the first time, before me, the thesis of Prof. E. C. Case, presented to the paleontological department of the University of Chicago, for his degree of Doctor of Philosophy, on “The Osteology and Relationships of Protostega"—a work requiring a great deal of study and research; and ably he accomplished his task.

Here, for the first time, he gives a nearly correct idea of the plastron. The carapace is largely unknown, and he makes the usual error of guessing at missing bones by concluding that there were no ossified neural arches. This he happily corrects,

when he demolishes Mr. G. R. Wieland’s new genus and species made out of Protostega, under the generic name of Archelon.
I have not had the long training necessary to even attempt to make a technical description according to rules of paleontology. My greatest glory has been that I have for nearly 30 years been a private soldier for science in the fossil fields of North America, gathering facts, new species, or old, the direct handiwork of the great Creator of all things; and consequently I know but little of the great literature which my labor and that of others has made possible. I have consequently left others to wrangle over the fragmentary relics of creative mind. I let one build up a genus or species for another to tear to pieces, spending a lifetime in proving that this theory was right and that was wrong. I find men’s theories come and go like the leaves of the forest, but the facts collectors gather, last for ever, as they are truths, and, are immortal. I write, then, from the standpoint of a man who from childhood has loved nature; and as a soldier in the great fossil camps, away from men and their works my mind has been little prejudiced in favor of this theory of evolution or that, and my habits and mode of thought are those of the camp, the battlefield, and not of the study and laboratory; my ideas then are original and they belong to me, and not to some other man.
When dear old Dame Nature, in whose services I have suffered so much, collecting her hidden treasures, “more rare than gold or silver,” was so kind (after 30 years’ labor among her cemeteries), as to allow me to stumble upon a perfect skeleton of Protostega gigas, in a low wash in a branch of Plum Creek, Grove [sic] Co., Kansas, last August, my joy knew no bounds, but unhappily my spirits reached their lowest ebb, when I found, after I had, with soft brush, uncovered it, I could not take it up in the exact condition in which it then lay before me. The rains of ages with the frosts of winter had entirely disintegrated the soft chalk. The desert shrubs that covers the chalk beds with verdure, had had many a dainty feast off the bones, and were rapidly eating them up; cattle also tramped over the helpless carcass. I found, when I had collected it, I had several thousand fragments where Prof. Cope had 800. And now I am slowly trying to restore them I have for months been afraid to unpack the specimen for fear I would endure the same suffering I did in the field, when for three days I tried to devise some means, without success, to save it in its natural position. But after re-reading Prof. Cope’s story of his successful work of restoring the type, I have gone to work, and am slowly and painfully cleaning and mending the bones; and I feel confident I will be able to restore entirely the complete carapace, a hitherto unknown quantity, and many other bones.

But it is the most nerve- and-patience-trying labor with which I am familiar. This tortoise lay down to die with muzzle pointed towards the setting sun; its skull and lower jaws in position; its cervical vertebræ reaching hack in a nearly straight line with the complete carapace, held firmly together to the central ridge, with 8 pairs of ribs expanded and united with each other the and to neural arches for about six inches each side of the apex; below this point they were free, two inches wide and uniformly so. The central ones were at right angles to the ridge, the others were narrower and shorter, radiating to the marginal bones, and this carapace was shoved bodily by the superficial pressure about two inches south of the left marginal bones.
A copy of a sketch I made in the field is attached to this article. The only measurements I made were after the bones were taken up, the lower ones leaving a distinct cast in the chalk. From the point of the lower jaws to end of tail was 8 1/2 feet; across the central marginal to its fellow was 6 feet. The skull was, as I remember, nearly a foot long. In the carapace (that lay on top of everything except where some of the arch, or long bones protruded between the spoke-like ribs), the neural arches were securely united lengthwise by beautiful sutures, and were beveled down into a shallow valley, where the union took place. Each arch also was beveled down laterally to join by sutures the proximal expanded portions that projected above and beyond the rib beads, which joined parts of the specialized vertebræ below. So we have a dorsal, elevated central ridge, broken by low places. These arches are heavy bones like rounded blunt inverted wedges, and all are beautifully sculptured. The middle crest occupied more than 2/3 of the central line in the middle of the carapace.
The animal, as I have said, lay down to die on its stomach, as did Prof. Cope’s. The four great plates of the plastron were not uniformly thin, but an inch thick in the centre, beveled off to a thin fingered margin, which interlaced with those of their fellows, and, contrary to Prof. Case’s description, along the middle line, as I believe.

I saw no signs of the great fontanelle he mentioned. There might have been a small one that escaped my notice owing to the bones of the endoskeleton which overlaid these plates. These bones were all present under the carapace as far as the forearm. To complete the plastron in front and behind, the front ones I especially remember, were peculiar, triangular-shaped bones, sickle-shaped in front, where they were an inch thick, with upper and lower edges nicely rounded off to admit the passage of the fore limbs; posteriorly they were beveled down thin, and fingered, interlacing with those of the large central plates, and as I believe, the apex of each joined the first and last marginals.
All the marginals wore in their natural position and completed the arch to each side. There were at least 16, as there were 16 ribs, the right angled, or lightly beveled ends of the ribs rested in a shallow socket, formed by the overlapping lemma of bone from the central pert of the thickened outer lips of the marginals. This part of the marginals, in the specimen described by Case, prove it to be a younger animal. As in mine, the sharp right angle has been worn down and rounded above and below, and the rib pits are nearer the upper surface.
Proximally the marginals are beveled down into thin fingered margins, that interlace with the fingers of the other bones of the plastron, but they are not united with the carapace, the caves or pits referred to holding the ribs in place. Therefore, we have in Protostega, a huge tortoise. My specimen when alive must have weighed in the neighborhood of a ton, with proportions the same as in modern tortoises, and not three times as long as it was broad, as Cope describes it. The plastron was completely ossified or nearly so, while along the central line of the neural arches of the carapace, the bones were united to form the peak of the roof for a distance of about six inches either side of that line. I will close by saying that the peak of “the first great roof” had straddle boards on, and a row of shingles, but its architect forgot to finish shingling, and left the rafters uncovered to the eaves. I have part of another Protostega, a third larger, I judge from the limb end other bones. As these bones are all well known, I will say nothing of them in this paper.