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Architects of the Berkeley legacy of Cenozoic molluscan paleontology - part I
by Carole S. Hickman

Following an initial phase of geological and paleontological reconnaissance along the western margin of North America, molluscan paleontology moved beyond basic taxonomic description and established itself as a major academic discipline at both the University of California, Berkeley, and Stanford University. The Berkeley legacy began to take shape with the formation of the Department of Paleontology and appointment of John Campbell Merriam as its first professor.

Merriam completed his Ph.D. in Munich under the direction of Karl A. von Zittel after finishing an undergraduate degree in geology at Berkeley, where he had been inspired by Joseph LeConte. In 1894, Merriam returned to Berkeley and joined the faculty of the geology department. Although the architectural footprint for the legacy of Cenozoic molluscan paleontology was not created until establishment of the Department of Paleontology in 1901, it was in the cradle of the geology department that Merriam mentored Charles Edwin Weaver, who went on to a distinguished and influential 43-year career of active research and teaching at the University of Washington. Weaver's monumental three-volume monograph of the paleontology of the Tertiary of Oregon and Washington is a dog-eared primary reference for researchers working today on fossil mollusks of the Pacific Coast. An interesting note, Weaver did not drive. He is said to have taken a bus from Seattle and then to have walked to field sites in the Cowlitz Formation in southwestern Washington, where he often worked from dawn to dusk and slept on the ground at the outcrop.

Students of Merriam who had the greatest impact on the field during this initial academic phase were Roy Ernest Dickerson, Earl Leroy Packard, and Bruce Lawrence Clark. Dickerson (Ph.D. 1914) had published five substantial papers on Eocene molluscan faunas within two years of completing his degree and went on to become Curator of Invertebrate Paleontology at the California Academy of Sciences. Packard (Ph.D. 1916) published his systematic monograph of mactrid bivalves the same year that he completed his degree and went on to become Professor of Paleontology at the University of Oregon. Clark (Ph.D. 1914) remained at Berkeley, succeeding Merriam in 1918.

John Merriam in 1931 Bruce L. Clark was best known for his work on Tertiary molluscs
Left: John Merriam in 1931. Though known more for his work in vertebrate paleontology, Merriam served as mentor and teacher to a number of students who went on to make significant contributions to molluscan paleontology. Right: Bruce L. Clark was best known for his work on Tertiary molluscs but he published on a broad range of topics. During his years at UCMP he made considerable additions to the museum's invertebrate fossil holdings.

Clark not only succeeded Merriam in the Department of Paleontology, but also became the first director of the Museum of Paleontology when it was established in 1921. During the next 30 years, Clark and his students broadened the Merriam tradition of field collection, faunal documentation, systematic description and revision, and creation of a molluscan biostratigraphic framework for the eastern Pacific margin. Some of Clark's students left basic molluscan paleontological research for careers in the oil industry. Although they did not assume prominent academic positions, they contributed important molluscan faunal and taxonomic monographs, catalogs, and new theoretical insights and ideas about climate change, molluscan provinces and paleobiogeography, speciation, nomenclature and classification, migration and faunal exchange, genetics, variation, and mechanisms of evolution.

Clark's own research and publication during the years of his Berkeley professorship were formidable. Two years after completing his degree, Clark had already published monographic studies of the molluscan faunas of the San Pablo Group and the San Lorenzo Series (an impressive 376 pages plus 61 plates).

But he is best known and most often cited for his monographic work on Tertiary bivalves (1925, 43 new species and a new genus) and papers on Pacific Coast Eocene faunas and biostratigraphy. Less well known are his contributions to the nature of species, the mechanisms of speciation, and processes of dispersal and migration underlying the geographic distribution of Tertiary mollusks. He joined the debate among geneticists over the role of natural selection and adaptation, arguing from paleontological data in support of Sewall Wright's arguments for the importance of isolation and genetic drift. It is remarkable and sad that Clark was never promoted to full professor. His strong advocacy for the existence of Oligocene strata on the Pacific Coast and his involvement in the controversial "Oligocene debate" appear to have worked against him.

During the Clark era there was considerable informal joint mentorship by molluscan paleontologists at major west coast institutions, and perhaps not surprisingly, Annie Alexander, UCMP benefactress, was notably generous in her support of molluscan field work by graduate students at other institutions as well as at Berkeley. One of Clark's most influential students was Hubert Gregory Schenck (Ph.D. 1926), who came to Berkeley after completing his masters thesis on the Eugene Formation under the direction of Earl Packard at the University of Oregon. Although Schenck spent a significant part of his career as a US government scientific advisor in the Far East and served as a Major in the Army during World War II, his academic influence was immense. He taught the first west coast course in micropaleontology and worked to "induce a number of young women to take up work in micropaleontology" as a pathway into a field dominated by men. With Berkeley micropaleontologist Robert M. Kleinpell, Schenck proposed and defined the Refugian Stage of the west coast Tertiary, and he played a major role in arguing for the existence of Oligocene strata on the Pacific Coast. Schenck's 1926 monograph of the Cassididae of western America expressed his concern with natural classification in the opening statement "The invertebrate paleontologist realizes that the ideal taxonomy expresses genetic relationship."

Among numerous successful students, two others should be noted. Charles Warren Merriam (Ph.D. 1933, Cenozoic turritellid gastropods) was the son of John Merriam. His dissertation on fossil turritellids of the Pacific Coast was remarkable and ahead of its time in treating topics not previously included in paleontological monographs. These included soft anatomy, ontogeny of the shell, homeomorphy, ecology, mode of life, feeding habits, larval dispersal, bottom conditions, and bathymetric limitations. The second was John Wyatt Durham (MA 1936, Ph.D. 1941), who succeeded Clark on the Berkeley faculty in 1947. Durham's 1944 monograph designating seven "megafaunal zones" in the Paleogene of western Washington was the first use of the Oppelian assemblage-based concept of zonation in the Pacific coast Tertiary.

The bibliographies of John Merriam, Bruce Clark, and their students fill many pages. The fossils they collected, described, and illustrated became the foundation of what is now the largest university collection of fossil mollusks in North America. That legacy continued with the work of Wyatt Durham and his students, which will be the focus of Part 2 of this account in the next edition of the UCMP News.

This account is extracted from a paper read at the 2008 annual meeting of the Western Society of Malacologists in a symposium honoring Ellen James Moore. Moore is part of our legacy because she studied with Earl Packard, a student of John Merriam.

* See Part II of this article in the February 2009 UCMP News. *

Merriam photo from Published Papers and Addresses of John Campbell Merriam, Volume 1; The Carnegie Institution of Washington, Washington, DC. 1938; Clark photo by Kee Coleman, from the UCMP Archives.