Jacques Armand Gauthier is a distinguished vertebrate paleontologist and a pivotal figure in the field of cladistics, significantly shaping our understanding of evolutionary biology. His academic journey began with a B.S. in zoology from San Diego State University, followed by a master’s degree in biological science, culminating in a PhD in paleontology from the University of California, Berkeley. His early work laid the groundwork for his future contributions, particularly his master’s thesis on the lizard clade Anguimorpha, which remains a cornerstone reference in morphological research.

As a professor at Yale University, Gauthier has excelled in both teaching and research, holding dual appointments in geology and geophysics as well as ecology and evolutionary biology. His groundbreaking PhD thesis introduced the first major cladistic analysis of Diapsida, advocating for the monophyly of dinosaurs. This work not only advanced the field but also initiated a paradigm shift in dinosaur phylogenetics, replacing traditional Linnaean classification with a more robust cladistic framework.

Gauthier’s influential publications have established him as a leading authority in the phylogenetic studies of Archosauria and Lepidosauria. His 1988 amniote paper is particularly notable for emphasizing the importance of taxon sampling in phylogenetic analysis, a concept that has become fundamental in the field. His collaborative efforts with notable scientists like Richard Estes and Kevin de Queiroz have further solidified his reputation, leading to the most widely accepted phylogeny of lizards and snakes.

In addition to his theoretical contributions, Gauthier advocates for the PhyloCode, aiming to modernize taxonomy. His ongoing research focuses on the anatomy and relationships of diapsids, particularly within the Scincomorpha clade. As a principal investigator on a National Science Foundation-funded project, he continues to push the boundaries of our understanding of lizard and snake evolution, ensuring his legacy as a transformative figure in paleontology.