Jacques Armand Gauthier (born June 7, 1948, in
New York City
New York, often called New York City (NYC), is the most populous city in the United States, located at the southern tip of New York State on one of the world's largest natural harbors. The city comprises five boroughs, each coextensive w ...
) is an American
vertebrate paleontologist,
comparative morphologist, and
systematist, and one of the founders of the use of
cladistics
Cladistics ( ; from Ancient Greek 'branch') is an approach to Taxonomy (biology), biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesiz ...
in biology.
Life and career
Gauthier is the son of Edward Paul Gauthier and Patricia Marie Grogan. He received a B.S. degree in zoology at
San Diego State University
San Diego State University (SDSU) is a Public university, public research university in San Diego, California, United States. Founded in 1897, it is the third-oldest university and southernmost in the 23-member California State University (CS ...
in 1973, a master's in biological science at the same institute in 1980, and a PhD in paleontology from the
University of California
The University of California (UC) is a public university, public Land-grant university, land-grant research university, research university system in the U.S. state of California. Headquartered in Oakland, California, Oakland, the system is co ...
, Berkeley, in 1984. Currently he is a professor of geology and geophysics and ecology and evolutionary biology and curator of vertebrate paleontology and vertebrate zoology at
Yale University
Yale University is a Private university, private Ivy League research university in New Haven, Connecticut, United States. Founded in 1701, Yale is the List of Colonial Colleges, third-oldest institution of higher education in the United Stat ...
. His master's thesis, the content of which was published in 1982, is a classic work on the paleontology and phylogeny of the lizard clade
Anguimorpha that remains a core reference for morphological research on
Xenosauridae
Xenosauridae is a family of anguimorph lizards whose only living representative is the genus '' Xenosaurus'', which is native to Central America. Xenosauridae also includes the extinct genera '' Exostinus'' and '' Restes''. Also known as knob-sca ...
and
Anguidae in particular. His PhD thesis constituted the first major
cladistic
Cladistics ( ; from Ancient Greek 'branch') is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is ...
analysis of
Diapsida, as well as arguing for the
monophyly
In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria:
# the grouping contains its own most recent comm ...
of the
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. He followed this with an important paper on the origin of
bird
Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...
s from
theropod
Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodom ...
s. This was the first detailed cladistic analysis of the theropod dinosaurs, and initiated a revolution in dinosaur
phylogenetics
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...
, in which cladistics replaced the Linnaean system in the
classification
Classification is the activity of assigning objects to some pre-existing classes or categories. This is distinct from the task of establishing the classes themselves (for example through cluster analysis). Examples include diagnostic tests, identif ...
and phylogenetic understanding of the dinosaurs.
Gauthier's corpus contributed the foundational phylogenetic studies of
Archosauria and
Lepidosauria
The Lepidosauria (, from Greek meaning ''scaled lizards'') is a Order (biology), superorder or Class (biology), subclass of reptiles, containing the orders Squamata and Rhynchocephalia. Squamata also includes Lizard, lizards and Snake, snakes. Sq ...
, two major amniote clades; and he was the primary author of the foundational and still widely cited phylogenetic study of
Amniota
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 C ...
as a whole. The phylogenetic character sets from his 1984 and 1986 works, the 1988 amniote paper, and the 1988 lepidosaur and
squamate
Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest Order (biology), order of reptiles; most members of which are commonly known as Lizard, lizards, with the group also including Snake, snakes. With over 11,991 species, it i ...
papers still form the core of essentially all gross-anatomy-based phylogenetic analyses of these groups, and as such are among the most highly cited papers in amniote morphology and paleobiology. The 1988 amniote paper is also frequently cited to demonstrate the importance of taxon sampling in phylogenetic analysis, in particular the importance of sampling rare or fossil taxa that can break 'long branches' along which convergence can occur.
Gauthier has argued together with
Kevin de Queiroz
Kevin de Queiroz is a vertebrate, Evolutionary biology, evolutionary, and Systematics, systematic biologist. He has worked in the phylogenetics and evolutionary biology of squamate reptiles, the development of a unified species concept and of a P ...
for replacing
Linnaean taxonomy
Linnaean taxonomy can mean either of two related concepts:
# The particular form of biological classification (taxonomy) set up by Carl Linnaeus, as set forth in his ''Systema Naturae'' (1735) and subsequent works. In the taxonomy of Linnaeus th ...
with the
PhyloCode
The ''International Code of Phylogenetic Nomenclature'', known as the ''PhyloCode'' for short, is a formal set of rules governing phylogenetic nomenclature. Its current version is specifically designed to regulate the naming of clades, leaving the ...
.
[Donoghue, Michael J., and Jacques A. Gauthier. "Implementing The Phylocode." ''Trends In Ecology & Evolution'' 19.6 (2004): 281–282. ''Academic Search Premier.'' Web. 11 Mar. 2013.] In addition to his theoretical work on systematics and taxonomy, Gauthier continues to study the anatomy and relationships of diapsids, particularly lepidosaurs. His lizard work currently focuses on
Scincomorpha
Scincomorpha is an infraorder and clade of lizards including skinks (Scincidae) and their close relatives. These include the living families Cordylidae (girdled lizards), Gerrhosauridae (plated lizards), and Xantusiidae (night lizards), as well a ...
, following on a career-long interest in the unusual clade
Xantusiidae. He is a principal investigator on the
National Science Foundation
The U.S. National Science Foundation (NSF) is an Independent agencies of the United States government#Examples of independent agencies, independent agency of the Federal government of the United States, United States federal government that su ...
-funded effort to reconstruct the phylogeny of lizards and snakes (
Squamata
Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest Order (biology), order of reptiles; most members of which are commonly known as Lizard, lizards, with the group also including Snake, snakes. With over 11,991 species, it i ...
) using gross anatomy and molecular structure, building on his earlier work in collaboration with Richard Estes and Kevin de Queiroz, which established the most widely accepted phylogeny of the group.
Footnotes
References
* (1988): Phylogenetic relationships within Squamata. ''In:'' : ''The Phylogenetic Relationships of the Lizard Families'': 15–98. Stanford University Press, Palo Alto.
* (1982): Fossil xenosaurid and anguid lizards from the early Eocene of Wyoming, and a revision of the Anguioidea. ''Contributions to Geology, University of Wyoming'' 21: 7–54.
* (1984): ''A cladistic analysis of the higher systematic categories of the Diapsida.''
hD dissertation Available from University Microfilms International, Ann Arbor, #85-12825, vii + 564 pp.
*
* (1988): A phylogenetic analysis of Lepidosauromorpha. ''In:'' : ''The Phylogenetic Relationships of the Lizard Families'': 15–98. Stanford University Press, Palo Alto.
*
* (1990): Ceratosauria. ''In:'' : ''The Dinosauria'': 151–168. University of California Press, Berkeley.
* (1992): Phylogenetic taxonomy. ''
Annu. Rev. Ecol. Syst.'' 23: 449–480.
* (1994): The diversification of the amniotes. ''In:'' : ''Major Features of Vertebrate Evolution: Short Courses in Paleontology'': 129–159. Paleontological Society.
*
External links
Yale Peabody Museum
{{DEFAULTSORT:Gauthier, Jacques
American paleontologists
American curators
Phylogenetics researchers
San Diego State University alumni
University of California, Berkeley alumni
Yale University faculty
American science teachers
American science writers
Living people
1948 births