Glenn Lowell Jepsen (b. 1903, d. 1974), the first to hold the appointment of Sinclair Professor of Vertebrate Paleontology at Princeton University, served the university, and the Princeton Geological Museum in particular, for some 49 years.

He was born in Lead, South Dakota, but his family moved to Rapid City while he was still a young child. After graduating from high school, he attended the University of Michigan for only a year, returning to South Dakota to teach English at the School of Mines and attending classes at the school part time. A chance encounter with William Sinclair on one of his many expeditions to the West in the 1920s led to Jepsen being persuaded to apply to Princeton. With this meeting, the 2 men began a friendship and working relationship that would last until Sinclair’s untimely death in 1935.

In 1927, Jepsen completed his undergraduate degree in geology and set out on his first collecting expedition to Wyoming. His commitment to fieldwork continued throughout his career, for as he put it, “Expeditions to collect long-dead bones and other fossils have been significant assets to our museum not only in obtaining valuable specimens but also in the more important sphere of influencing men’s lives.”

He continued at Princeton, receiving his Ph.D. in 1930 under Sinclair and W.B. Scott, and was appointed as an instructor in the Department of Geology the next year. His subsequent appointments included Curator of Vertebrate Paleontology in 1936, Assistant Professor in 1934, Associate Professor in 1940 and, as mentioned above, the Sinclair Professorship of Vertebrate Paleontology in 1946. In 1962, Yale University awarded him the Addison Emery Verrill Medal, one of that University’s highest honors. He served as Director of Princeton’s natural history museum from 1936 until his retirement in 1971. On his retirement, the Glenn L. Jepsen Fund in Natural History was established to support student research, particularly in vertebrate paleontology.

Jepsen was unwavering in his belief that the purpose of the university’s natural history museum was to provide Princeton’s students with an inestimable educational resource, to stimulate their “…interests in research, conservation, aesthetic enjoyment, and to heighten the human sense of life.” It is almost prophetic that in 1964 he wrote, “It is regrettable (and now regretted) in some museums that during bursts of short-sighted and provincial economy and cleanup activities the baby was thrown out with the bath water…. Princeton, of all places, must continue to preserve significant parts of the past, as it has done for more than a century in museums of both art and natural science, in order to fortify future education.”

Jepsen’s patient and persistent collecting of the Paleocene fauna of Polecat Bench in Wyoming resulted in Princeton’s possessing one of the best collections of this type in North America. Instead of amassing large collections spanning vast amounts of geological time and great geographical distances, Jepsen endeavored to understand as completely as possible the animals and environment that existed during one of the most crucial epochs in mammalian evolution, the Paleocene. The publications that resulted from this endeavor not only included descriptions of new genera and species, but also faunal analyses and, following in Sinclair’s footsteps, biostratigraphic correlations of the nonmarine North American Tertiary.