Ellis L. Yochelson (1928-2006) was both a paleontologist and a historian.  His paleontological studies centered on Paleozoic mollusks, especially gastropods, but also included scaphopods, chitons, and monoplacophorans.  In addition, he proposed the Phylum Agmata, and monographed the Late Cambrian “motorcycle tracks” made by Climacticnites.

His historical studies included the epic two-volume biography of Charles D. Walcott, the 75^th anniversary volume of the National Museum of Natural History (USNM), and his 2004 study of “…Natural History in Washington.”  Ellis’ bibliography has at least 300 entries. Ellis had a lifelong interest in natural history.  He joined the U.S. Geological Survey in 1952 and had his laboratory at the United States National Museum of Natural History, Smithsonian Institution. After retirement in 1985, he continued at the USNM as a Research Associate and Scientist Emeritus for the rest of his life. Ellis, and his wife Sally, hosted innumerable colleagues and students who came to the USNM to study.

Ellis was President of the Paleontological Society, he founded the Society’s annual short courses in 1978, and in 1969 he arranged the first North American Paleontological Convention (NAPC). The 2001 NAPC in Berkeley was dedicated to him.  In 2003, he received the Award of the History of Geology Division of the Geological Society of America.  Yochelson Ridge, in the Heritage Range of the Ellsworth Mountains, was named for him in honor of his Antarctic work. (See, 2007, American Paleontologist, v. 15, No. 1, p. 11).