A century of science in America

by Unknown

Extinct fishes of the Devonian of Illinois and Missouri and the Devonian and Carboniferous of Pennsylvania were made the subjects of his next researches, after which he described the peccaries of Ohio, and later, in a much larger and most important work, the Cretaceous reptiles of the United States (1865). Most of the fossils discussed in this last work are from the New Jersey Cretaceous marls and of them the most notable was the herbivorous dinosaur Hadrosaurus, the structure and habits of which, together with its affinities with the Old World iguanodons, Leidy described in detail. From Leidy’s descriptions and with his aid, Waterhouse Hawkins was enabled to restore a replica of the skeleton in a remarkably efficient way. This restoration for a long time graced the museum of the Philadelphia Academy of Natural Sciences and there was a plaster replica of it in the United States National Museum. These, together with plaster replicas of Iguanodon from the Royal College of Surgeons in London, gave to Americans their first real conceptions of members of this most remarkable group. The associated fossils from the New Jersey marls were chiefly crocodiles and turtles.

From 1853 to 1866 F. V. Hayden was carrying on a series of most energetic explorations in the West, especially in Nebraska and Dakota as then delimited, returning from each trip laden with fossils which were given to Leidy for determination. The results appeared in 1869 in Leidy’s Extinct Mammalian Fauna of Dakota and Nebraska, published as volume 7 of the Journal of the Philadelphia Academy. In this large volume no fewer than seventy genera and numerous species of forms, many of them new to science, were described, representing many of the principal mammalian orders; horses were, however, especially conspicuous. This last group led Leidy to the conclusion, afterward emphasized by Huxley, that North America was the home of the horse in geologic time, there being here a greater representation of different species than in any recent fauna of the world. Leidy’s interest in the horses, for the forwarding of which he made a large collection of recent material, extended over many years, as his first paper on the subject bears the date of 1847, the last that of 1890.

Next came the discovery of Eocene material from the vicinity of Fort Bridger, Wyoming, geologically older than the Nebraska and Dakota formations. This, together with specimens from the Green River and Sweetwater River deposits of Wyoming and the John Day River (Oligocene) of Oregon, was also referred to Leidy, and added yet more to the list of newly discovered species with which he had already become familiar in his earlier researches. The results of this study were published by the Hayden Survey in 1873, under the title “Contributions to the Extinct Vertebrate Fauna of the Western Territories.” This was the last of Leidy’s major works, but he continued up to the time of his death to report to the Academy concerning the various fossil forms that were submitted to him for identification. Of such reports the most important was one on the fossils of the phosphate beds of South Carolina, published in the Journal of the Academy in 1887.

As a paleontologist, Leidy ranks with Cope and Marsh high among those who enriched the American literature of the subject, but it must be remembered that this was but a single aspect of his many-sided scientific career, for he made many contributions of high order to botany, zoology, and general and comparative anatomy as well, nor did his knowledge and usefulness as an instructor of his fellow men keep within the limitations of these subjects.

Othniel Charles Marsh (1831–1899).

The sixth decade of the nineteenth century saw the beginning of the labors of several paleontologists who, like Leidy, were destined to raise the science of fossil vertebrates in America to the level of attainment of the Old World. They were, among others, Othniel Charles Marsh and Edward Drinker Cope. Of these the names of Marsh and Cope are linked together by the brilliance of their attainments, their contemporaneity, and the rivalry which the similarity of their pursuits unfortunately engendered. Marsh produced his first paleontological paper in 1862 (33, 278), Cope in 1864, but the latter died first, so that his life of research was shorter.

To Professor Marsh should be given credit for the first organized expedition designed exclusively for the collection of vertebrate remains, the results of which contain so much material that it has not yet entirely seen the light of scientific exposition. Marsh’s first trip to the West was in 1868, the first formal expedition being organized two years later. These expeditions, of which there were four, were privately financed except for the material and military escort furnished by the United States Government, and consisted of a personnel drawn entirely from the graduate or undergraduate body of Yale University. These parties explored Kansas, Nebraska, Wyoming, Utah, and Oregon, and returned laden with material from the Cretaceous and Tertiary formations of the West. Some of this is of necessity somewhat fragmentary, but type after type was secured which, with his exhaustive knowledge of comparative anatomy, enabled Marsh to announce discovery after discovery of species, genera, families, and even orders of mammals, birds, and reptiles which were unknown to science. The year 1873 saw the last of the student expeditions, and thereafter until the close of his life the work of collecting was done under Marsh’s supervision, but by paid explorers, many of whom had been his scouts and guides in the formal expeditions or had been especially trained by him in the East. In 1882, after fourteen years of the experience thus gained, Marsh was appointed vertebrate paleontologist to the United States Geological Survey, which relieved him in part of the personal expense connected with the collecting, although up to within a short time of his death his own fortune was very largely spent in enlarging his collections. After his connection with the Survey was established, Marsh had two main purposes in view in making the collections: (1) to determine the geological horizon of each locality where a large series of vertebrate fossils was found, and (2) to secure from these localities large collections of the more important forms sufficiently extensive to reveal, if possible, the life histories of each. Marsh believed that the material thus secured would serve as key or diagnostic fossils to all horizons of our western geology above the Paleozoic, a belief in which he was in advance of his time, for few of his contemporaries appreciated the value of vertebrates as horizon markers. The result of the fulfilment of his second purpose saw the accumulation of huge collections from all horizons above the Triassic and some Paleozoic and Triassic as well. These contained some very remarkable series, each of which Marsh hoped to make the basis of an elaborate monograph to be published under the auspices of the Survey. One can visualize the scope of his ambitions by the fact that no fewer than twenty-seven projected quarto volumes, to contain at least 850 lithographic plates, were listed by him in 1877. These covered, among other groups, the toothed birds (Odontornithes), Dinocerata, horses, brontotheres, pterodactyls, mosasaurs and plesiosaurs, monkeys, carnivores, perissodactyls and artiodactyls, crocodiles, lizards, dinosaurs, various birds, proboscideans, edentates and marsupials, brain evolution, and the Connecticut Valley footprints. Much was done towards the preparation of these memoirs, as evidenced by the long list of preliminary papers, admirably illustrated by woodcuts which were to form the text figures of the memoirs, which appeared with great regularity in the pages of the Journal for a period of thirty years. Of the actual memoirs, however, but two had been published at the time of Marsh’s death in 1899—the Odontornithes in 1880 and the Dinocerata in 1884. One must not overlook, however, the epoch-making Dinosaurs of North America, which was published by the Survey in 1896, although it was not in the form nor had it the scope of the proposed monographs. This was not due to lack of application, for Professor Marsh was an indefatigable worker, but rather to the fact that the program was of such magnitude as to necessitate a patriarchal life span for its consummation. As it is, Professor Marsh’s fame rests first upon his ability and intrepidity as a collector, ready himself to brave the very certain hardships and dangers which beset the field paleontologist in the pioneer days, and also by his judgment and command of men to secure the very adequate services of others and so to direct their endeavors that the results were of the highest value. The material witness to Marsh’s skill as a collector lies in the collections of the Peabody Museum at Yale and in the Marsh collection at the United States National Museum, the latter secured through the funds of the United States Geological Survey. Together they constitute what is possibly the greatest collection of fossil vertebrates in America, if not in the world; individually, they are second only to that of the American Museum in New York City, the result of the combined labors of Osborn and Cope and their very able corps of assistants.

As a scientist Marsh possessed in large measure that wide knowledge of comparative anatomy so necessary to the vertebrate paleontologist, and as a consequence was not only able to recognize affinities and classify unerringly, but also to recognize the salient diagnostic features of the form before him and in few words so to describe them as to render the recognition of the species by another worker relatively easy. The publication of hundreds of these specific diagnoses in the Journal constitutes a very large and valuable part of that periodical’s contribution to the advancement of our science. Marsh’s method of indicating forms by so brief a statement leaves much to be done, however, in the way of further description of his types, which in many instances were but partially prepared.

Yet another important service which Marsh rendered to science was the restoration of the creatures as a whole, made with the most painstaking care and precision through assembling the drawings of the individual bones. These restorations have become classic, embracing as they did a score or more of forms, of beast, bird, and reptile. They also were published first in the Journal, although they have subsequently been reproduced in text-books and other works the world over. Part of Marsh’s popular reputation, at least, which was second to that of no other American in his line, was due to his skill in attaining publicity, for his papers, of whatever extent, were carefully and methodically sent to correspondents in the uttermost parts of the earth, and thus the Marsh collection has reflected the fame of its maker.