Samuel Wendell Williston
Samuel Wendell Williston (July 10, 1852 – August 30, 1918) was an American educator, entomologist, and paleontologist who was the first to propose that birds developed flight cursorially (by running), rather than arboreally (by leaping from tree to tree). He was a specialist on the flies, Diptera. He is remembered for Williston's law, which states that parts in an organism, such as arthropod limbs, become reduced in number and specialized in function through evolutionary history.
Also recorded as S. W. Williston · Williston
Samuel Wendell Williston

Public domain
- Died
- 1918. · Chicago.
- Nationality
- United States.
- Occupation
- paleontologist, entomologist, zoologist, illustrator, university teacher and pedagogue.
- Fields
- dipterology, paleontology, zoology and entomology.
- Education
- Kansas State University and Yale University.
- Known for
- North American Plesiosaurs: Elasmosaurus, Cimoliasaurus, and Polycotylus and The Osteology of the Reptiles.
- Honours
- Fellow of the Geological Society of America.
- Languages
- English.
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Documentary summary
Samuel Wendell Williston (July 10, 1852 – August 30, 1918) was an American educator, entomologist, and paleontologist who was the first to propose that birds developed flight cursorially (by running), rather than arboreally (by leaping from tree to tree). He was a specialist on the flies, Diptera. He is remembered for Williston's law, which states that parts in an organism, such as arthropod limbs, become reduced in number and specialized in function through evolutionary history.
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Note VALÉORINE
Samuel Wendell Williston (1851–1918) was an entomologist, illustrator and paleontologist, among other activities, of American nationality. The entomologist was born in Boston and died in Chicago.
Samuel Wendell Williston was educated at Kansas State University and Yale University. The entomologist worked for University of Chicago and University of Kansas and was a member of American Academy of Arts and Sciences, American Philosophical Society and National Academy of Sciences. Activity centred on dipterology, entomology and paleontology.
Among the works are North American Plesiosaurs: Elasmosaurus, Cimoliasaurus, and Polycotylus and The Osteology of the Reptiles. Languages used include English. Honours include Fellow of the Geological Society of America.
Composed from admitted, traceable facts · 26 September 2026
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wikidata · Q1376111 · wikipedia · Samuel Wendell Williston
In this article
Early life
Early life
Samuel Wendell Williston studied at Kansas State University and Yale University. The recorded working language is English. The field of work recorded is dipterology, paleontology and zoology. Employment is recorded with University of Kansas and University of Chicago. Works named in the authority record are North American Plesiosaurs: Elasmosaurus, Cimoliasaurus, and Polycotylus and The Osteology of the Reptiles. Distinctions recorded are Fellow of the Geological Society of America.
Williston was born in Boston, Massachusetts to Samuel Williston and Jane A. Williston née Turner. As a young child, Williston's family travelled to Kansas Territory in 1857 under the auspices of the New England Emigrant Aid Company to help fight the extension of slavery. He was raised in Manhattan, Kansas, attended public high school there, and graduated from Kansas State Agricultural College (now Kansas State University) in 1872, afterwards receiving a Master of Arts from that institution. In 1874, he went on his first field fossil hunting expedition for Othniel Charles Marsh at Yale University under the mentorship of Benjamin Franklin Mudge, and led his first expedition in 1877. With Mudge, Williston discovered the first fossils of the dinosaurs Allosaurus and Diplodocus. He was noted for painstakingly illustrating the finds. In 1880, he matriculated to Yale University, for several years was a post-graduate student and faculty member. Around this time, he proposed the first explicit model for the terrestrial origin of bird flight (i.e., that dinosaurs developed flight by running along the ground rather than jumping from trees). Williston returned to Kansas in 1890, to take a position on the faculty at the University of Kansas as a professor of geology and anatomy. In 1899, he was named the first Dean of the new School of Medicine there. He was also a member of the state boards of health and medical examiners. In 1902, Williston left Kansas again, and took the chair of paleontology at the University of Chicago. Williston was a fellow of the Geological Society of America, a foreign correspondent for the London Geological and Zoölogical societies, a member of the United States National Academy of Sciences, a member of the American Academy of Arts and Sciences, and a member of the American Philosophical Society. He was president of the Kansas Academy of Science, and in 1903 became president of the Society of Vertebrate Paleontology. He was the author of several books, and the Smithsonian Institution now administers an endowment fund in his name.
Work on Diptera
Work on Diptera
Although never employed as a professional entomologist, Samuel W. Williston was a Fellow of the Entomological Society of America since 1915, and was well-renowned specialist on the taxonomy and systematics of flies (Diptera). He became the first North American specialist on this group, publishing over 50 books and papers, and naming more than 1250 species. His best-known works were the three editions of the Manual of North American Diptera (1888, 1896, 1908).
The Osteology of the Reptiles
The Osteology of the Reptiles
In 1925, Williston published (post hum?) a comprehensive survey of the reptilian skeleton, which was a precursor to the monumental Osteology of Reptiles by A. S. Romer.
Williston's law
Williston's law
Williston noticed that, over evolutionary time, the modular and serially repeated parts distinguishing animal groups exhibited trends in numbers and types. For instance, ancient vertebrates were characterized by mouths that contained mostly similar teeth, whereas recent vertebrates are characterized by mouths with different kinds of teeth, adapted for biting, tearing, and compacting food; differences ultimately characterized different diets, with carnivores bearing incisors, canines and carnassials, and grazers bearing mostly molars. In 1914, Williston declared that "it is also a law in evolution that the parts in an organism tend toward reduction in number, with the fewer parts greatly specialized in function". However, empirical studies have not always confirmed this generalization. For instance, a study of the evolution in the number of branchiostegal rays in osteichthyans has failed to support a generalized trend towards reduction. Instead, this series of elements shows an early burst pattern (rapid evolution early in the history of the group, followed by a decrease in evolutionary rate).

Illustration of Seymouria (from nearly complete specimen, from above) from The Osteology of the Reptiles (1925)
Samuel Wendell Williston · Internet Archive identifier: osteologyofrepti00will The Osteology of the Reptiles, page 4, Fig. 1
Life and career
Dated record
Life and career
Explore 1851–1918
The full dated record · 3 entries
1851
Samuel Wendell Williston born at Boston.
1908
Manual of North American Diptera / by Samuel W. Williston. (Wellcome Collection).
1918
Samuel Wendell Williston died at Chicago.
Places
Named by the record
Places
Only places the record itself states, plotted where the house gazetteer settles their coordinates. Nothing is inferred from a name or a nationality.
Boston.
Birth place
Chicago.
Death place
Primary material
Documents and archives
scholarly publication
- SAMUEL WENDELL, WILLISTON, The Canadian Entomologist, 1919
Scholarly · Crossref registry · 1919
- The osteology of the reptiles, by Samuel Wendell Williston... arranged and edited by William King Gregory, 1925
Scholarly · Crossref registry · 1925
- Williston, Samuel Wendell (1851-1918), paleontologist and entomologist, American National Biography Online, 2000
Scholarly · Crossref registry · 2000
- Williston, Samuel Wendell, Encyclopedia of Entomology
Scholarly · Crossref registry
Institutional database
- Wikidata, structured authority record Q1376111: Samuel Wendell Williston
Scholarly · Wikimedia Foundation
authority file
Notes from the source article
Cited by Wikipedia
Notes from the source article
These works are cited by the source article, in its own numbering. They are recorded as its citations, not as sources VALÉORINE has verified.
- 1.Blackmar 1912.
- 2.Williston 1898.
- 3.Samuel W. Williston. www.nasonline.org.
- 4.Samuel Wendell Williston. American Academy of Arts & Sciences. 2023-02-09.
- 5.APS Member History. search.amphilsoc.org.
- 6.Smithsonian. Williston Diptera Research Fund. Department of Entomology, National Museum of Natural History.
- 7.Entomological Society of America. List of ESA Fellows.
- 8.Beckemeyer 2009.
- 9.Williston, Samuel W. The osteology of the reptiles. Harvard University Press. 1925.
- 10.Williston, Samuel Wendell. Water Reptiles of the Past and Present. University of Chicago Press. 1914.
- 11.Ascarrunz, E. On trends and patterns in macroevolution: Williston's law and the branchiostegal series of extant and extinct osteichthyans. BMC Evolutionary Biology. 19. 1. 117. 2019. 10.1186/s12862-019-1436-x.
References
Citations
References
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scholarly publication
SAMUEL WENDELL, WILLISTON, The Canadian Entomologist, 1919Crossref registry
Institutional witnessscholarly publication
The osteology of the reptiles, by Samuel Wendell Williston... arranged and edited by William King Gregory, 1925Crossref registry
Institutional witnessInstitutional database
Wikidata, structured authority record Q1376111: Samuel Wendell WillistonWikimedia Foundation
Institutional witnessscholarly publication
Williston, Samuel Wendell (1851-1918), paleontologist and entomologist, American National Biography Online, 2000Crossref registry
Institutional witnessscholarly publication
Williston, Samuel Wendell, Encyclopedia of EntomologyCrossref registry
Institutional witnessauthority file
VIAF cluster 54250657 for Samuel Wendell Williston, aggregating national library name authorities.OCLC
Secondary witnessreference work
Secondary witness
People, houses and institutions
Knowledge graph
People, houses and institutions
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Studied at
1- Yale UniversityOrganisation
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The Encyclopedia exists whether or not anything is for sale. Corrections are recorded rather than overwritten, and every version of this record is kept. Published 14 August 2026.
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