René Zaragüeta i Bagils


My research concerns the theory and development of three-item analysis (3ia). 3ia is a theory of taxa classification in systematics and biogeographic areas in historical biogeography. It is characterized by an additional analytical stage, in which the hypotheses of homology are decomposed into elementary hierarchies, i.e. two of them are more closely related than any is to the third (hence the name 3ia). In 3ia, it is not necessary to introduce extragroups, no taxa / characters (or areas / taxa) matrices are used, there are no question marks, etc...

The results of the research in 3ia have been implemented in the computer program package LisBeth


Postal address:

René Zaragüeta i Bagils
Sorbonne Université, MNHN, CNRS, EPHE, Institut de Systématique, Évolution, Biodiversité, ISYEB,
75005 Paris, France,
Laboratoire Informatique et Systématique

MNHN Département Histoire de la Terre
Bâtiment de Géologie CP48
57 rue Cuvier 75005 Paris (France)

tél :
@ : Rene.Zaragueta_Bagils >


I teach organismic biology and systematics in the first three years of Paris6 university.

I also teach in the Museum-Paris6 university master "Systematics, Evolution, Paleobiodiversity" three-item analysis, cladistic biogeography (Area cladistics), epistemology and philosophy of science

I am responsible for a module of the research school of the MNHN, entitled "Three-item analysis in systematics and biogeography".


2018 Rineau, V., Zaragüeta Bagils, R., Laurin, M. : Impact of errors on cladistic inference: simulation-based comparison between parsimony and three-taxon analysis. Contributions to Zoology, 87 (1) 25-40.

2017 Khalloufi, B., Dutheil, D., Mora, T., Zaragüeta Bagils, R. : Mesozoic clupeomorphs of North Africa : diversity and phylogeny. Research & Knowledge, 3 (2) : 46-49.

2016 Zaragüeta Bagils, R. & Pécaud, S. : Why should cladograms be dichotomous?. Chap. 10 in Williams, D., Schmitt, M. & Wheeler, Q. (eds.) :The Future of Phylogenetic Systematics: The Legacy of Willi Hennig. Cambridge University Press.

2016 Pinna, M. d., Bockmann, F. A., Zaragüeta Bagils, R. : Unrooted trees discovered independently in philology and phylogenetics: a remarkable case of methodological convergence. Systematics and Biodiversity 2016, 1-10.

2015 Lecointre, G. De Wever, P. Ekström, S. Gargaud, M. Gounelle, M. Klein, E. Longo, G. Martin, H. Pavé, A. Walliser, B. Zanda,B. & Zaragüeta Bagils, R. : Catégories et classification face au changement. Chap. 13 in Gargaud, M. & Lecointre, G. (dir.) : L’évolution, de l’univers aux sociétés. Objets et concepts. Editions Matériologiques.
Flyer here

2015 Cecca, F. & Zaragüeta Bagils, R. : Paléobiogéographie. Collection Géosphères dir. P. de Wever. EDP Sciences, Paris.
Flyer here

2015 Zaragüeta, R. : Les deux biogéographies. Biosystema 30, Editions Matériologiques.

2015 Rineau, V, Grand, A, Zaragüeta Bagils, R., Laurin, M.. :Experimental systematics: sensitivity of cladistic methods to polarization and character ordering schemes. Contributions to Zoology, 84 (2) 129-148

2015 Ung, V, Zaragüeta Bagils, R., Williams, D. : Comparative biogeography of Southeast Asia and the West Pacific region. Biological Journal of the Linnean Society.

2014 Grand, A, Zaragüeta Bagils, R., Duque-Velez, L., Ung, V. : A cladistic re-analysis of the Gadiformes (Teleostei, Paracanthopterygii) using three-item analysis. Zootaxa 3889:525-552.

2012 Zaragüeta Bagils R., Ung, V., Grand, A., Cao, N. & Ducasse, J. : LisBeth: New cladistics for phylogenetics and biogeography. Comptes Rendus Palevol, 11 : 563-566

2011 Zaragüeta Bagils R. : Ancêtres in Biosystema 28 : 41-62. L’arbre du vivant existe-t-il ? (V. Malécot,
N. Léger et P. Tassy, coord.). Société Française de Systématique, Paris

2010 Khalloufi, B., Zaragüeta Bagils, R. & Lelièvre, H. : Rhombichthys intoccabilis, gen. et sp. nov. (Ellimmichthyiformes, Clupeomorpha, Teleostei) from the Cenomanian (Upper Cretaceous) of Ein Yabrud, Middle East. Anatomical description and phylogenetic implications. Journal of Vertebrate Paleontology 30(1) : 57–67

2010 Ung V., Dubus G., Zaragüeta-Bagils R., & Vignes-Lebbe R. : Xper²: introducing e-Taxonomy. Bioinformatics, 26 (5) : 703-704.

2009 Zaragüeta Bagils, R., Bourdon E., Ung V., Vignes-Lebbe R. & Malécot V. : Comments on the International Code of Area Nomenclature. Journal of Biogeography, 38 : 1617-1619

2009 Cao N., Bourdon E., El Azawi M., & Zaragüeta-Bagils R. : Three-item analysis and parsimony, intersection tree and strict consensus: a biogeographical example. Bulletin de la Société Géologique de France, 180 (1) : 13-15

2008 Cao N., Le Pechon, T. & Zaragüeta Bagils R. : Does minimizing homoplasy really maximize homology? MaHo: A method for evaluating homology among most parsimonious trees. Comptes Rendus Palevol, 7 (1) : 17-26

2008 Lelièvre, H., Zaragüeta-Bagils, R. & Rouget, I. : Temporal information, fossil record and phylogeny. Comptes Rendus Palevol 7 : 27–36

2007 Zaragüeta-Bagils, R. & Bourdon E. : Three-item analysis: Hierarchical representation and treatment of missing and inapplicable data.Comptes Rendus Palevol 6 : 527–534

2007 Cao N., Zaragüeta-Bagils, R. & Vignes-Lebbe R. : Hierarchical representation of the hypotheses of homology. Geodiversitas 29 (1) : 5-15.

2007 Jacques F. Gallut C. Vignes-Lebbe R. & Zaragüeta-Bagils, R. : Resolving phylogenetic reconstruction in Menispermaceae (Ranunculales) using fossils and a novel statistical test. Taxon 56 (2) : 379-392

2006 Zaragüeta-Bagils, R., Bourdon E., Rouget I & Lelièvre H. : Arbres phylogénétiques et chronologie. Géochronique 98: 44-45.

2004 Zaragüeta-Bagils, R., Lelièvre H. & Tassy P. : Temporal paralogy, cladograms, and the quality of the fossil record, Geodiversitas 26, 381-389

2004 Zaragüeta-Bagils, R. : Basal clupeomorphs and the Ellimmichthyiform phylogeny. Mesozoic Fishes 3. Systematics, Paleoenvironments and Biodiversity (G. Arratia et A. Tintori, eds.). Verlag Dr. Friedrich Pfeil, Munich, 391-404

2002 Zaragüeta-Bagils, R., S. Lavoué, A. Tillier, C. Bonillo et G. Lecointre : Assessment of otocephalan and protacanthopterygian concepts in the light of multiple molecular phylogenies. Comptes Rendus de l'Académie des Sciences – Série Biologies 325 : 1-17.

2001 Zaragüeta-Bagils, R. : Les Alosa fossiles et la notion de genre en systématique phylogénétique. Bulletin Français de Pêche et Pisciculture 362/363 : 1059-1066.

2001 Zaragüeta-Bagils, R., et H. Lelièvre : Âges et noms versus caractères et phylogénie : le problème de l'ajustement entre la stratigraphie et la phylogénie. in Biosystema 19 : 169-185. Systématique et Paléontologie (P. Tassy et A. de Ricqlès, eds.). Société Française de Systématique, Paris.

Communications dans des congrès interationaux

2007 Zaragüeta-Bagils, R. & Bourdon, E. : Three-item analysis: representation and treatment of missing and non-applicable character-states". Conférence introductive à la session Méthodologie. Palaeobotany and the Evolution of Plants: Current Issues. Organisation Francophone de Paléobotanique et the Linnean Society of London Palaeobotany Specialist Group. Collège de France, Paris.

2007 Cao, N Le Péchon, T. & Zaragüeta-Bagils, R. : Minimizing homoplasy is not maximazing homology : a method for choosing among most parcimonius trees. Palaeobotany and the Evolution of Plants: Current Issues. Organisation Francophone de Paléobotanique et the Linnean Society of London Palaeobotany Specialist Group. Collège de France, Paris.

2007 Lelièvre, H. Rouget, I. & Zaragüeta-Bagils, R. : Information temporelle, registre fossile et phylogénie. Palaeobotany and the Evolution of Plants: Current Issues. Organisation Francophone de Paléobotanique et the Linnean Society of London Palaeobotany Specialist Group. Collège de France, Paris.

2006 Zaragüeta-Bagils, R., Cao, N., Rouget, I. Tassy, P. & Lelièvre, H. : HiFi: a proposed solution for measuring the fit of phylogenies to stratigraphy. 2nd International Palaeontology Congress, Beijing, RP Chine.