Eric O. Callen and the Early Years of Coprolite Analysis

Bryant, V.M. Jr. (1) and Glenna Dean (2)
    (1) Department of Anthropology (TAMU-4252), Texas A&M University, College Station, Texas 77843-4352 (
    (2) Historic Preservation Division, Office of Cultural Affairs, 228 E. Palace Avenue, Room 320, Santa Fe, New Mexico 87501 (

The detailed analysis of human coprolites, as a recognized field of science, is barely 40 years old. Dr. Eric O. Callen, the founder and developer of the discipline in its modern form, has been dead for more than 30 years yet the techniques and ideas he developed and perfected continue to guide the discipline today. Callen ushered in the modern age of human coprolite analysis during the late 1950s and early 1960s, yet today those analyses have extended into areas than even he would never have dreamed possible. During his decade of coprolite work he worked alone and with missionary zeal to convince archaeologists, botanists, zooarchaeologists, and anyone else who might be willing to listen to arguments about the importance of prehistoric human fecal research. Almost from the beginning many fellow scientists considered his research as unimportant and frivolous yet Callen never wavered from his commitment until his early and untimely death in 1970.

Eric Callen was an unlikely person to become the "father" of coprolite analysis. He had no anthropology or archaeology background and had he spent most of his professional career as a professor of plant pathology at McGill University in Canada after receiving a doctorate in botany from the University of Edinburgh in Scotland. His first exposure to the study of coprolites came by accident when an archaeologist gave him some prehistoric human feces that had been recovered during the excavation of an early agricultural site in the coastal region of Peru. Callen's initial interest in the human fecal remains consisted only of a search for the fungal remains of potential plant pathogens that might have infected prehistoric varieties of Peruvian maize, which may have been harvested and eaten by humans. That initial coprolite study led Callen into new dimensions of research that became the basis for prehistoric diet reconstructions based on the wide variety of micro and macrofossils he discovered during his first analysis. His new research interest was far removed from his academic classes and studies of plant pathogens, and his study of feces earned him little praise or respect from his botanical colleagues, most of whom believed he was wasting valuable research time.

During the ten years he devoted to developing standards for coprolite processing, identification, and analysis he worked alone, he never taught a course on the subject, he received no awards or praise for his pioneering efforts, and during that decade he had only one graduate student who was just beginning his studies when Callen died. During his brief decade of research Callen's only work space was a tiny room no larger than a small bathroom yet he laid the important groundwork for many others who later used his ideas and techniques to complete detailed studies of human coprolites. Today, Callen would be gladdened to learn that others built upon his initial coprolite research and extended it to include a wide variety of studies of plant macrofossils, pollen, phytoliths, amino acids, pollen concentration values, gas chromatographic data, faunal studies, and most recently the extraction and identification of DNA from human feces using PCR techniques.