Since the Smithsonian's founding in 1846, our fossil collections have grown steadily and now include tens of millions of fossil vertebrates, invertebrates, plants, and microfossils. Most were discovered during expeditions led by government scientists, including our own research curators and staff, but important additions have come in the form of transfers from university collections, donations from private citizens, occasional strategic purchases, and trades with other museums. Historically, large natural history museums such as ours engaged in mutually beneficial specimen trades as a way of broadening their collections and expanding their exhibits. Trading opportunities typically arose when a museum's collecting activities yielded multiple well-preserved specimens of a single species.
In the late 1920s and early 1930s, field expeditions to Idaho from the National Museum of Natural History (then known as the United States National Museum) yielded abundant fossils subsequently used in trades. A cattle rancher named Elmer Cook had discovered fossil bones near Hagerman, Idaho, in 1928 and given them to Dr. H. T. Sterns of the United States Geological Survey. Sterns forwarded the fossils to Dr. James Williams Gidley, a vertebrate paleontologist at the United States National Museum, who immediately identified some of them as the bones of a previously unknown fossil horse. Greatly interested, Gidley arranged for an expedition to the Hagerman area early the following year. Gidley and Cook collected fossils in the area in both 1929 and 1930, with three tons of specimens returned to the museum in 1929 alone. This take represented the greatest accumulation of horse remains ever discovered in one location, and in 1930 the locality was by no means exhausted. Deteriorating health prevented Gidley from returning to the area, but Norman Boss (Chief Preparator in the Department of Geology) led an expedition to Hagerman in 1931, and C. Lewis Gazin followed with an expedition in 1934. All together, the expeditions yielded more than 130 skulls, numerous associated jaws, and enough bones for 10 complete skeletons.
Before his death in 1931, Gidley identified the horse fossils found at Hagerman as a new species, Plesippus shoshonensis. Plesippus was significant in that it represented an intermediate evolutionary form between an early horse, Pliohippus, and the modern horse, Equus. (Later scientific study revealed that the horses instead belonged to an early species of Equus, Equus simplicidens, which had been discovered and named earlier.) In yielding so many well-preserved bones of so many individuals of all ages and both sexes, the Hagerman Horse Quarry - today also known as the Gidley Horse Quarry - provided an extraordinary view into the ecology and biology of an early modern horse.
A grouping of Hagerman horse specimens, including three adults and one "newborn," was displayed for decades in our fossil exhibits. Click to zoom.
Other vertebrate remains found in the vicinity of the horses include those of fish, frogs, turtles, snakes, birds, and a variety of both large and small mammals, suggesting that the site may have been a small pond or watering hole. Paleoartist Jay Matternes used fossil and geologic evidence to reconstruct the ancient environment of the Hagerman site and the animals that lived there. His mural was mounted behind the horse skeletons. Click to zoom.
The extensive Hagerman collection placed the Museum in the enviable position of having more horse specimens than it needed for research or exhibit at the time and created the opportunity to trade with other museums that did not have horse specimens well-represented in their collections. Letters in our archives document numerous offers of, and requests for, horse skeletons and skulls, beginning in the early 1930s.An exchange negotiated in 1931-32 with the Colorado Museum of Natural History (now the Denver Museum of Nature and Science) traded a skeleton of Equus simplicidens for a skeleton of the early rhinoceros Trigonias osborni (USNM 12724), and a 1932 exchange with the Los Angeles County Museum of History, Science and Art (now the Natural History Museum of Los Angeles County) netted our museum a Pleistocene horse, Equus occidentalis (USNM 12593). In 1933, an exchange with the Royal Ontario Museum yielded skulls of the Late Cretaceous dinosaurs Prosaurolophus maximus (USNM 12712) and Edmontosaurus regalis (USNM 12711) from Alberta, and, as described in an earlier post, a partial skeleton of the Late Jurassic dinosaur Camarasaurus (USNM 13786) was obtained from the Carnegie Museum of Natural History in Pittsburgh in 1935 in exchange for a complete horse skeleton, eight skulls, and five months of Charles W. Gilmore's time.
Among the exhibit quality specimens received in trade for our Hagerman horse material were (above, top row) a rhinoceros, Trigonias osborni, from Colorado, a Pleistocene horse, Equus occidentals, from California and (bottom row) the skulls of two hadrosaurid dinosaurs, Edmontosaurus regalis and Prosaurolophus maximus, from Alberta, Canada. Click photos to zoom.
Although James Gidley's Hagerman horse fossils will not be exhibited in the National Fossil Halls when they reopen in 2019, the rhino, horse, and Edmontosaurus, shown above, and the Camarasurus will be there, a reminder of the many ways that horse trading has benefited our exhibits.
This is the second post describing the impact that James Gidley (1866-1931) had on our fossil collections and exhibits. It is based in part on a recent biographical essay by Department of Paleobiology volunteer Mark Lay. The essay can be accessed here, and the earlier post about Gidley's Cumberland Cave collection and the Indiana Mastodon can be found here.