1941: Paleontology, Vertebrate

Field Work.

This year was marked by the first annual field meeting of the newly formed Society of Vertebrate Paleontology. The meeting, under the sponsorship of the University of Nebraska, was held in western Nebraska and was attended by more than a hundred persons representing 24 institutions. Many problems of upper Tertiary stratigraphy were studied and discussed.

Collecting this year by American institutions was necessarily confined almost entirely to North America. A number of museums and universities continued projects already under way, those of particular importance being the work of the American Museum in South Dakota, the Oligocene studies of the Philadelphia Academy of Science in Wyoming, the important early Tertiary work of the National Museum in Utah, similar work by the Field Museum of Chicago in western Colorado, the continuation of the Nebraska and Kansas State Museums of work in their respective states, collecting by Harvard University in the Permian beds of Texas and also the opening of new middle Tertiary deposits by this institution in Florida, work in the western states by Princeton and Yale Universities and by the Carnegie Museum of Pittsburgh, and the continuation of collecting activities in the Pacific Coast and Plains region by the University of California and in southern California by the California Institute of Technology.

Exhibition.

Various museums continued to add to their exhibits of fossil vertebrates. The American Museum of Natural History put on display a skeleton of Ectoconus, perhaps the oldest mammal skeleton fully known and exhibited. In addition this institution prepared for exhibit the skull of a gigantic crocodile found in the Cretaceous beds of Texas. This specimen represents a crocodilian of unprecedented size, rivaling the dinosaurs with which it was contemporaneous in bulk and power.

At the Field Museum of Natural History a new display showing evolution in certain rodents was put on view. At Yale University the revision of the fossil exhibits was continued, while at the Museum of Comparative Zoology at Harvard some choice new material from the Texas Permian beds was made available to the public.

Research and Publications.

In January the report of the Committee on the Nomenclature and Correlation of the Continental Tertiary of North America was published. This report will do much to facilitate stratigraphic discussions and studies in the future. In this connection there might be mentioned also the guide for the first annual field conference of the Society of Vertebrate Paleontology, written by C. B. Schultz and T. M. Stout and in itself an important contribution to Tertiary stratigraphy.

R. Denison published a paper interpreting the soft anatomy of the primitive vertebrate, Bothriolepis, a subject of much controversy in the past. R. M. Sternberg described the anatomy of the skull in the crossopterygian fish Eusthenopteron, important because of its position as a structural ancestor for the land vertebrates, while B. Schaeffer made further contributions to the knowledge of these types of fishes. Descriptions of fossil teleost fishes were made by G. M. Conrad and by L. David.

In a series of joint studies by W. K. Gregory, H. Raven and B. Schaeffer, the origin and development of limbs in the early tetrapods was discussed, while the latter of these authors made additional contributions on the evolution of the foot structure in the vertebrates. An important paper by H. J. Sawin described in detail the cranial anatomy of the Permian amphibian Eryops, while A. S. Romer described the structure of the external scales in this animal.

S. P. Welles made additional contributions to the anatomy of the primitive reptile, Diadectes. E. H. Colbert and R. G. Chaffee studied anew the type material of the Triassic phytosaur, Rutiodon, and discussed the implications of this material on the relationships of the phytosaurs.

In the field of mammalian paleontology perhaps the outstanding event was the appearance of the final volume of W. B. Scott's monographic study of the White River fauna. This volume describes and discusses the perissodactyls or odd-toed hoofed mammals, and with its completion a comprehensive study of the well known fossils from the Big Badlands of South Dakota is for the first time available. J. J. Burke described new rabbits collected by the Asiatic expeditions of the American Museum of Natural History. Of particular importance is the description by G. G. Simpson of a new giant rodent from the White River fauna, a quite unexpected element in this supposedly well-known assemblage of mammals. An additional contribution on rodents was made by H. J. Cook and J. T. Gregory, while this latter author described a sea cow from Florida.

Several important papers were published by G. G. Simpson on extinct cats from North America. C. S. Johnston and W. G. Christian described a new dog from the Upper Tertiary of Texas, while E. H. Colbert described a new 'bear-dog,' Hemicyon, from Nebraska. This latter author also presented anatomical and phylogenetic studies of Archaeomeryx, a primitive ruminant from Mongolia secmingly approximately ancestral to the later horned and antlered mammals, and of a Pliocene aardvark from the Island of Samos in the Mediterranean. G. M. Lyon described a Miocene sea lion from California; G. Meade a Miocene hedgehog from Nebraska, while E. H. Barbour and C. W. Hibbard described a new mastodont from Kansas. R. A. Stirton discussed at some length the development and nomenclature of characters in fossil horse teeth.

J. Clark described an early primate from Wyoming while the distinguished anatomist, F. Weidenreich discussed at length the factors involved in the increase of the brain during mammalian evolution.

New faunas were described by C. L. Gazin and by C. W. Hibbard, the former a Paleocene assemblage from Utah, the latter a Pliocene fauna from Kansas.

This year saw the additional use of statistics in Paleontology. G. G. Simpson utilized statistics in various papers, and in addition made contributions on the principles of statistics as applied to paleontology and zoology.

Finally there should be mentioned C. W. Gilmore's account of the history of Vertebrate Paleontology at the United States National Museum.