James Allen Hopson (born 1935) is an American

paleontologist Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geolo ...

and

professor Professor (commonly abbreviated as Prof.) is an Academy, academic rank at university, universities and other tertiary education, post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin ...

(now retired) at the

University of Chicago The University of Chicago (UChicago, Chicago, or UChi) is a Private university, private research university in Chicago, Illinois, United States. Its main campus is in the Hyde Park, Chicago, Hyde Park neighborhood on Chicago's South Side, Chic ...

. His work has focused on the

evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

of the

synapsids Synapsida is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida (which includes all extant rept ...

(a group of

amniotes Amniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial and semiaquatic vertebrates. Amniotes evolved from amphibious stem tetrapod ancestors during the ...

that includes the

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s), and has been focused on the transition from basal synapsids to mammals, from the late

Paleozoic The Paleozoic ( , , ; or Palaeozoic) Era is the first of three Era (geology), geological eras of the Phanerozoic Eon. Beginning 538.8 million years ago (Ma), it succeeds the Neoproterozoic (the last era of the Proterozoic Eon) and ends 251.9 Ma a ...

through the

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

Eras. He received his

doctorate A doctorate (from Latin ''doctor'', meaning "teacher") or doctoral degree is a postgraduate academic degree awarded by universities and some other educational institutions, derived from the ancient formalism '' licentia docendi'' ("licence to teach ...

at Chicago in 1965, and worked at

Yale Yale University is a private Ivy League research university in New Haven, Connecticut, United States. Founded in 1701, Yale is the third-oldest institution of higher education in the United States, and one of the nine colonial colleges ch ...

before returning to Chicago in 1967 as a faculty member in

Anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

, and has also been a research associate at the

Field Museum of Natural History The Field Museum of Natural History (FMNH), also known as The Field Museum, is a natural history museum in Chicago, Illinois, and is one of the largest such museums in the world. The museum is popular for the size and quality of its educationa ...

since 1971. He has also worked on the

paleobiology Paleobiology (or palaeobiology) is an interdisciplinary field that combines the methods and findings found in both the earth sciences and the life sciences. An investigator in this field is known as a paleobiologist. Paleobiology is closely ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

s, and his work, along with that of Peter Dodson, has become a foundation piece for the modern understanding of duckbill crests, social behavior, and variation.

Selected publications

* *Hopson, J.A. & H.R. Barghusen. 1986. An analysis of therapsid relationships. In: The Ecology and Biology of Mammal-like Reptiles (Ed. by N. Hotton III, P. D. MacLean, J. J. Roth, & E. C. Roth), pp. 83–106. Washington DC: Smithsonian Institution Press. *Hopson, J.A. 1991. Systematics of the non-mammalian Synapsida and implications for patterns of evolution in synapsids. In: Controversial Views on the Origin of Higher Categories of Vertebrates (Ed. by H. P. Schultze & L. Trueb), Ithaca: Cornell University Press. *Allin, E.F. & J.A. Hopson. 1991. Evolution of the auditory system in Synapsida ("mammal-like reptiles" and primitive mammals) as seen in the fossil record. In: The Evolutionary Biology of Hearing (Ed. by D. B. Webster, A. Popper, and R. Fay), New York: Springer-Verlag. *Wible, J. R. & J. A. Hopson. 1993. Basicranial evidence for early mammal phylogeny. In: Mammal Phylogeny (Ed. by F. S. Szalay, M. J. Novacek, & M. C. McKenna), New York: Springer-Verlag. * *

References

Bibliography

A. W. Crompton, Farish A. Jenkins, Jr., Susan Hopson, Timothy J. Gaudin, and Matthew T. Carrano, "James Allen Hopson: A Biography", pages 507-515 in ''Amniote Paleobiology: Perspectives on the Evolution of Mammals, Birds, and Reptiles: A volume honoring James Allen Hopson'', edited by Matthew T. Carrano, Timothy J. Gaudin, Richard W. Blob, and John R. Wible. The University of Chicago Press, Chicago & London, 2006

External links

Organismal Biology & Anatomy
faculty homepage

faculty homepage
Recent work
on the evolution of the mammalian ear {{DEFAULTSORT:Hopson, James Living people American paleontologists People associated with the Field Museum of Natural History 1935 births Presidents of the Society of Vertebrate Paleontology