Perissodactyl Project

Morris Skinner
Paleontologist Morris Skinner working on fossil horses from the Frick Collection , 1974
fossil horse
Fossil horse - Pliohippus pernix: Miocene, Nebraska
fossil tapir
Fossil tapir - Tapirus johnsoni: Miocene, Nebraska
Fossil rhino
Fossil Rhino - Menoceras arikarense: Miocene, Wyoming
Fossil rhino 2
Fossil Rhino - Galushaceras levellorum: Miocene, Nebraska
Substandard storage
Substandard storage - fossil rhinos
Substandard storage - brontotheres
Substandard storage - brontotheres
Brontothere skulls padded with cotton wadding

Perissodactyls, also known as odd-toed ungulates, are a group of herbivorous mammals that are defined by having middle toe that is larger than the others, with the plane of symmetry of the foot passing through it (called a mesaxonic foot). Most species have three digits on the hindfoot and three or four on the forefoot, but in some only a single digit, the third, remains. There are three groups of perissodactyls extant today; horses, rhinos, and tapirs. A further two groups are known only from the fossil record; these are the chalicotheres and titanotheres.

The AMNH fossil mammal collection contains 18,919 catalogued specimens of perissodactyl in 151 genera, including 71 genotypes and 231 holotypes, and ca. 45,000 uncataloged specimens, occupying two whole floors of the Childs Frick Building (also known as Building 3A). Over 40,000 of these are fossil horses; this is by far the largest collection of extinct horses of in the world, covering the entire evolutionary history of the group, from its first appearance during the Eocene epoch, around 55 million years ago, through to the present day, and providing the foundation for much of our understanding of the systematics and evolution of horses.

The AMNH perissodactyl collection has formed the basis for a number of major monographic studies, from H.F. Osborn's magisterial study of the titanotheres, published in 1929, through to more modern work, such as Don Prothero's 2005 monograph on the evolution of rhinos in North America. Numerous Ph.D. students have used the collection as the basis for their doctoral researches, some of whom have gone on to notable careers in paleontology; these include Michael Woodburne, Bruce Macfadden, and Margery Coombs.

Despite the importance of the collection, there have been a number of areas where it has fallen short of the highest standards of curation. Many of the specimen cabinets were over 75 years old, and did not meet current conservation standards. Oversized specimens often were stored 2 to 4 deep on substandard shelving, meaning that over half of them could not be accessed without moving other specimens. Many specimens were stored in boxes without any protection, or padded with cotton wadding, whose fibers can snag on specimens, causing damage. Specimen trays were made of cardboard which can produce acidic byproducts that damage specimen labels and the various adhesives and consolidants used in specimen preparation. Finally, although development of electronic databases for the Division have made on-line access to complex georeferenced locality data a reality for some specimens, detailed locality data are dispersed across the collection and associated archives, in card catalogs, shipping records, field notes, and maps. In order to provide high quality, georeferenced data to collection users, these disparate data sources will need to be consolidated.

Over the next three years, as part of the 3A project, and with the assistance of funding from the National Science Foundation, the perissodactyl collection will be undergoing a major overhaul. Physical housing of the collection will be improved by the purchase of 166 new cabinets and 40 storage racks; replacement of damaged drawers and specimen trays; and lining of stores and trays with archival standard foam. Access to specimen data will be improved by the georeferencing of the c. 1,800 specimen localities associated with the perissodactyl collection; enhancing on-line specimen descriptions; and addressing the backlog of uncataloged material in the collection.

As part of the NSF-funded project, the Division will be developing on-line resources to enable guided, in-depth access to the collection and associated records. The first of these should be available by 2009, but additional information will be added to this website from time-to-time as the project proceeds.