Armand continued teaching at the University Paris 7 (this is one of the several universities into which the former Université de Paris was split following the famous student protests of May 1968) as Maître de Conférences until he was named Professor in the same university on January 1, 1983 to succeed to Professor Yves François, who had retired (Meunier, 2000). He was quickly promoted (January 1, 1987) to First Class Professor (equivalent to Full Professor in North America) in the same university, where he remained until 1995, when he was nominated to the prestigious chair “Biologie Historique et Évolutionnisme” (Historical and Evolutionary Biology) of the Collège de France, an institution that was established by the king of France François I in the 16th century. Incidentally, that nomination was important for me too because I first came to France to temporarily replace Armand in teaching the courses at the University of Paris 7 that his duties at the Collège de France made it impossible for him to fulfill.

Armand's teaching responsibilities were as diversified as his research interests. As early as 1962, as Assistant, he handled laboratory tutorials. He taught taxonomy-oriented zoology and botany short field courses at the Roscoff field station (Brittany), in Fontainebleau, and Franchard (Île-de-France). He taught a variety of courses at Paris 7: metazoan evolution (focusing on arthropods), vertebrate comparative anatomy, general paleontology, principles of phylogenetics, histology, and a bit of evolutionary theory and of history of zoology. In addition, he gave many public seminars in various symposia or as guest speaker. Finally, at the Collège de France, he gave a different course every year, on evolutionary and paleontological topics. Each year, the course included a symposium that involved French and other guest speakers; these have included, to name only a few who came to France for this purpose, Dennis Carter (Stanford, California), Kevin Padian (University of California, Berkeley), Rainer Schoch (Staatliches Museum für Naturkunde, Stuttgart, Germany), and Tim Smithson (Cambridge Regional College, England). The French speakers are too numerous to name; just in the last year (2008–2009), the symposium, entitled “150 ans après l’Origine des espèces : du darwinisme de Darwin à l’évolutionnisme contemporain” (150 years after the Origin of species: from Darwin's Darwinism to contemporary evolutionary theory) involved Jean Dutch (UPMC), Jean Gayon (University Paris 1), Guillaume Lecointre (MNHN), Hervé Le Guyader (UMPC), Annie Mamecier (National Ministry of Education), Pascal Tassy (MNHN), and Michel Veuille (EPHE: École Pratique des Hautes Études).

Armand's teaching responsibilities also included defining the content of various courses and programs (mostly from the third to fifth years). As President of the UPMC Scientific Council, he fought the strong tendency that pushed many biology departments (especially in France) to completely abandon morphology to concentrate solely on subjects deemed more “modern,” such as molecular biology, genetics, and physiology. He was in charge of at least three Master's programs (DEA) in the field of evolutionary biology, systematics, and paleontology.

Another form of teaching at which Armand has excelled is the publication of semi-popular papers. He has so far published at least 120 of them (Laurin, this issue), and will no doubt publish more in the coming years. He started early in his career because his first was published in 1967, when he was less than 30 years old. He published regularly in various French semi-popular magazines, such as La Recherche, Pour la Science (the French edition of Scientific American), the Encyclopedia Universalis, and various other magazines and books. The range of topics covered in these papers was even broader than Armand's research interests because they included papers on history of life and genetics, evolutionary theory, and the Cambrian evolutionary radiation.

Armand was co-director (along with Yves François) of the team “Formations squelettiques” as early as 1973, and became its sole leader in 1982. That team included several scientists interested in bone histology (not necessarily for all their careers): Vivian de Buffrénil, Jacques Castanet, Jorge Cubo, Hélène Francillon-Vieillot, François Meunier, Alexandra Quilhac, Jean-Yves Sire, Louise Zylberberg, and myself. In the 1990s, Armand attempted to integrate a molecular biologist (Marc Girondot) to add another approach to the study of vertebrate mineralized tissues. The subsequent nomination of Laure Bonnaud (a molecular phylogeneticist) to our team strengthened this initiative, at least in the short-term. Ultimately, however, that attempt was not altogether successful, and both molecular biologists left the team, either when an opportunity for a promotion arose (Marc Girondot), or to be in an environment where a greater diversity of molecular studies could be better supported (Laure Bonnaud).

Armand also participated in the organization of several scientific meetings, either as the head of the organizing committee, as the co-organizer, or as a member of the organizing committee. These include, in addition to the first ISPN meeting (Section 3.2), the following. As chief organizer: “La croissance périodique” (periodic growth), a symposium of the Société Zoologique de France (1979); “Formes panchroniques et fossiles vivants” (Panchronic forms and living fossils), a symposium in the annual meeting of the Société Zoologique de France organized to celebrate the centenary of the death of Charles Darwin (1982); “Table ronde contrat européen Erasmus sur l’anatomie fonctionnelle” (Symposium on the European Erasmus contract on functional anatomy; 1992). As co-organizer: “Classification et phylogenèse” (Classification and phylogeny), symposium of the Société Zoologique de France (1977); “Premier symposium international sur les écosystèmes continentaux du Mésozoïque” (First international symposium on Mesozoic continental ecosystems; 1978); “Second international symposium on the genus Triturus” (1986); “Table ronde autour du livre de Stephen Jay Gould La vie est belle” (Symposium on Stephen Jay Gould's book Wonderful Life: The Burgess Shale and the Nature of History; 1991). As member of the organizing committee: “Ontogenèse et évolution” (Ontogeny and evolution; 1986); First World Herpetological Congress (1989).

Armand took on several editorial duties, especially of French journals. He served on the editorial committee of the “Annales de Paléontologie”, a journal in which he published at least 26 papers (Laurin, 2011, this issue), of “L’Année Biologique”, of the “Bulletin de la Société Herpétologique de France”, and of the Belgian Journal of Zoology. He was co-editor of the “Annales des Sciences Naturelles” from 1986 and to 2000, when that journal ceased publication (de Ricqlès, 2000a). Most importantly, he has been one of the four co-editors-in-chief (along with Philippe Taquet, Yves Coppens, and Kevin Padian) of the “Comptes Rendus Palevol” of the Académie des Sciences de Paris since that journal appeared in 2002, and has published about one paper per year in that journal (Laurin, 2011).

Although most of Armand's later works focused on paleohistology (Laurin, this issue), his first works on bone histology focused on extant taxa. His very first paper (published in two parts), derived from his doctoral thesis, focused on morphogenesis of the urodele Pleurodeles waltlii (de Ricqlès, 1964 and de Ricqlès, 1965). In that paper, Armand noted that the medullary cells seem to have an exogenous origin, rather than deriving from the chondroblasts or chondrocytes, thus refuting an earlier hypothesis.

In the same paper, Armand also noted that endochondral ossification occurs late in P. waltlii, and attributed this to its aquatic lifestyle. This was only the first observation of a long series that would pave the way for much more detailed studies on the relationship between bone microanatomy and lifestyle (aquatic to terrestrial). His Habilitation thesis included what was probably the most thorough treatment of this question at the time, at least on extinct vertebrates. Thus, Armand used bone microanatomy to infer the lifestyle of many early vertebrates, such as Paleozoic stegocephalians (de Ricqlès, 1981) and amniotes (de Ricqlès, 1974). These works triggered many later investigations about the relationship between bone microanatomy and lifestyle in extant vertebrates using more quantitative techniques by various scientists (Fish and Stein, 1991, Leclair et al., 1993, Stein, 1989 and Wall, 1983), including several by his former doctoral student Vivian de Buffrénil (de Buffrénil and Schoevaert, 1989, de Buffrénil et al., 1986 and Wiffen et al., 1995), myself (Laurin et al., 2006 and Steyer et al., 2004), and our own students (Canoville and Laurin, 2009, Houssaye, 2009 and Laurin et al., 2009). Similarly, paleobiological investigations into the lifestyle of various early vertebrates were also undertaken by several other labs (Green et al., 2010, Ray and Chinsamy, 2004 and Ray et al., 2005) or by Armand's former students and collaborators (de Buffrénil et al., 1990a, de Buffrénil et al., 1990b and de Ricqlès and de Buffrénil, 1995), as well as mixed studies that included both investigations on extant and extinct taxa, that can provide more rigorous inferences (Canoville and Laurin, 2010 and Kriloff et al., 2008) or document changes in bone microanatomy following habitat changes (de Buffrénil et al., 2010). All these works, and many others that are not evoked here for lack of space, were at least to an extent inspired by Armand's pioneering efforts.

Armand proposed a very detailed classification of bone tissues (de Ricqlès, 1975, de Ricqlès, 1976, de Ricqlès, 1977a, de Ricqlès, 1977b, de Ricqlès, 1978a and de Ricqlès, 1978b) and standardized nomenclature in that field, much like Linnaeus’ great influence on biological nomenclature in the 18th century. The parallel can be drawn further because Armand's treatment of bone classification and nomenclature shows several similarities with taxonomic monographs. Thus, his papers provide a diagnosis, they describe the mode of formation, and provide synonymy (with authorship of each synonym) and subdivisions of each tissue type. The nomenclature mostly reflected the density and orientation of vascularization, the orientation of collagen fibers, and the density of secondary osteons. This provided an invaluable reference to decrypt the histological literature because many names had been given to various tissue types. For instance, what Armand called “fibrolamellar bone with primary longitudinal and circular osteons” (de Ricqlès, 1975) was called “in toto concentrico Knochen” by Gebhardt (Gebhardt, 1901), “laminare bone” by Meyburg (Meyburg, 1904), “Type II” by Foote (Foote, 1916), and “laminaren Periostknochen” by Gross (Gross, 1934). Clearly, as in taxonomy, communication is facilitated by a standardized nomenclature (de Queiroz and Gauthier, 1994 and Laurin, 2008). The widespread acceptance of Armand's nomenclature of bone tissues (Botha and Chinsamy, 2005, Chinsamy and Tumarkin-Deratzian, 2009, Green et al., 2010, Ray et al., 2005, Scheyer et al., 2010 and Witzmann, in press) and the fact that it was based on a thorough survey of a large body of literature may justify calling him “the great synthesizer of bone histology”.

An important part of Armand's habilitation thesis, published in several parts (de Ricqlès, 1975, de Ricqlès, 1976, de Ricqlès, 1977a, de Ricqlès, 1977b, de Ricqlès, 1978a and de Ricqlès, 1978b), was a study of the functional significance of bone tissues. This concerned especially the relationship between bone tissue architecture (of vascularization, of collagen fiber orientation, etc.) and deposition rate. That work included a thorough, critical review of the literature, such as the important papers by Enlow and Brown, 1956, Enlow and Brown, 1957 and Enlow and Brown, 1958 and work by Amprino that established a link between bone tissue structure and deposition rate, a link now known as Amprino's rule (Amprino, 1947). It also included mostly qualitative, but numerous observations on original bone sections. That work laid the foundation for more quantitative studies on this topic (de Margerie et al., 2002 and de Margerie et al., 2004) that largely confirmed, with a few exceptions, Armand's findings. For instance, quantitative studies confirmed that avascular bone is deposited more slowly than vascular bone (de Margerie et al., 2002), and radial bone is deposited faster than laminar bone (de Margerie et al., 2004).

Armand collaborated with younger scientists whom he helped to train in this field in recent quantitative studies. In some of these studies evoked above (de Margerie et al., 2002 and de Margerie et al., 2004), vital staining was used, as Meunier and Pascal (1981), Castanet and Naulleau (1985), and Castanet et al. (2000) had done earlier, to mark bone tissues at various dates to more rigorously and precisely determine how much time had elapsed between the deposition of various layers. In another study (Cubo et al., 2008), a new three-dimensional model was developed to partition variance of a dependent character (here, bone growth rate) into three components. In this case, these components were historical (phylogenetic), functional (mass-corrected resting metabolic rate), and structural (relative perimeter of growth, measured as the ratio between the sum of osteonal and peripheral accretional surfaces and the sole peripheral accretional surface). Although that model can be represented in various ways, and it was introduced with a series of partly overlapping circles (Fig. 3), such a three-dimensional model can also be conceptualized as a cubic one, and I cannot resist calling it “Cubo's cube”, in honor of the first author of the paper that introduced it. That name is fitting not only because of the authorship, but also because there is an amusing (but not statistically significant!) parallel between the careers of Jorge Cubo and Pablo Picasso, the founder of cubism: both were born in Malaga, worked for some years in Barcelona, and then moved on to Paris (where Picasso spent the last part of his career; the same is likely to happen to Cubo because he is already Professor at the UPMC).

Armand's interests in vertebrate paleontology led him to participate in several field trips. In 1967, he went with Raymond Desparmet and Philippe Taquet to Niger to prospect Permian and Triassic localities (Fig. 4). There, the team discovered fossils in various strata, including the Permian captorhinid Moradisaurus grandis that Armand later described with P. Taquet (de Ricqlès and Taquet, 1982).

In 1975, Armand accompanied Bernard Battail and Jean-Michel Dutuit (both from the Natural History Museum, Paris) to prospect Permo-Triassic strata in the Moroccan Atlas. They discovered new fossiliferous sites that yielded temnospondyls (Dutuit, 1972, 1976b), diplocaulid nectrideans (Dutuit, 1976a, 1988a), therapsids (Dutuit, 1988b, 1989a, b), and phytosaurs and brought back eight tons of fossils still in their matrix. Although Armand did not describe the taxa discovered in that field trip, he participated in a histological and skeletochronological study (Steyer et al., 2004) of one of the temnospondyls, Dutuitosaurus ouazzoui, initially described by J.-M. Dutuit under the name Metoposaurus ouazzoui (Dutuit, 1976b).

Armand prospected in the Permian of Oklahoma, at the famous Dolese Brothers Quarry, with John Bolt (in 1980 and 1981). Armand then used the rich collections of the Field museum to study tooth replacement in Captorhinus through numerous sections in various planes, a type of study that could be performed, before the advent of CT-scanners, only on taxa represented by abundant material (de Ricqlès and Bolt, 1983).

In his last field trip, Armand accompanied Anusuya Chinsamy, who later also became a famous paleohistologist, in the Permo-Triassic Karoo basin. There, they collected various stegocephalians, including some therapsids and archosauriforms. During that trip, Armand also had the opportunity to borrow material from the rich Permo-Triassic collections of the museums of Cape Town and Johannesburg.

Some of Armand's works in paleontology had a strong phylogenetic component. Thus, two of his papers include some of the first cladograms of Paleozoic stegocephalians ever to be published (de Ricqlès, 1984 and de Ricqlès and Taquet, 1982). These papers included a fairly detailed phylogeny of captorhinids. The supporting datasets were derived from a paper by Eugene Gaffney and Malcolm McKenna (Gaffney and Mc Kenna, 1979) that contains what may be the earliest cladogram of any early stegocephalian taxon (in this case, Captorhinidae). However, at that time, cladistics had not yet become the default, nearly compulsory method in phylogenetic inference that it has since become (at least for morphologists). I remember, from my post-doc days (1994–1996) in Berkeley (California), seeing the following warning near the door of a laboratory: “Warning, dangerous cladists, free radicals”. In the early 1980s, systematics was deeply divided between proponents of numerical taxonomy (phenetics) and cladistics (the “new systematics” had already become old and even though it still had its adepts, especially among morphologists, it was clearly on its way out, squeezed between the two other, more “modern”, quantitative and a priori objective methods). This episode was admirably reviewed by Joseph Felsenstein (Felsenstein, 2001), who mentions (p. 466), among other anecdotes, that at the Numerical Taxonomy meeting at Harvard, in 1979: “The two camps sat on opposite sides of the auditorium (cladists on the right, others on the left) and the atmosphere was totally partisan. When a speaker from one side made a point, the other groaned, while adherents murmured approval”. In light of this, Armand's early adoption of cladistics may be seen as visionary.

Armand was perhaps even bolder in supporting the development of phylogenetic nomenclature. Back in 2003, I was planning the First International Phylogenetic Nomenclature Meeting with the help of a small committee that included, among a few other members, Armand. At that time, some of our French colleagues (including some at the Muséum) were not thrilled that the Museum had agreed to host that meeting. Indeed, the development of phylogenetic nomenclature triggered a vivid debate between its proponents and systematists who want to retain rank-based nomenclature (Laurin, 2008). Some of the latter have even considered phylogenetic nomenclature and the PhyloCode “at best as a mistake and at worst as a criminal operation against the study of biodiversity” (Dubois, 2005) or “pure folly” (Carpenter, 2003). Yet, Armand supported this initiative as best he could, helped to publicize the meeting (Laurin and de Ricqlès, 2004 and Laurin et al., 2003), and obtained a grant from the Fondation Hugot that enabled us to organize the banquet in the historic restaurant “Le Train Bleu” and to provide gastronomic coffee break food such as fresh pastries, cheese, cold cuts, and wine. My former thesis advisor, Robert R. Reisz, who is certainly a connaisseur of good food, even called this event “The best-tasting meeting I ever attended” (personal communication from Reisz at the meeting). The meeting can be considered a success because it launched an international society (Laurin and Cantino, 2004 and Laurin and de Ricqlès, 2004), the ISPN (International Society for Phylogenetic Nomenclature), that supervises the development of the PhyloCode (Cantino and de Queiroz, 2010). That society has met twice more since then, in 2006 (Laurin and Cantino, 2007) and 2008 (Laurin and Bryant, 2009) and has fostered developments in phylogenetic nomenclature. Armand integrated principles of phylogenetic nomenclature in his scientific papers and activity reports for the Collège de France from the late 1990s onwards (de Ricqlès, 2000b).

Armand does not consider himself a historian of sciences, but he has long been interested in that topic. He published biographies of Jean Piveteau and Charles L. Camp. In his biography of Piveteau (de Ricqlès, 1991), he focused on Piveteau's influence on the Parisian school of paleontology. He argued that his influence resulted in increased international communication, the introduction of new technologies, and closer ties with biology (much of the previous Parisian paleontology was more geologically and stratigraphically oriented). Piveteau required technical and methodological rigor of his collaborators, but left them complete intellectual freedom; there was no established dogma that could not be refuted, provided that the argument was based on factually correct data and logical reasoning. Of course, as in most other paleontological communities, much of that research rested on detailed anatomical descriptions.

But Armand did not use his historical and comparative perspective only to discuss the past, but also to enlighten us about the present. Thus, in an admirable, very lucid short note “Quelques réflexions sur la recherche fondamentale en France” (de Ricqlès, 2007), Armand vividly highlighted various problems that many scientific communities in the world may face to an extent, but that seem especially acute in France. These include an excessive administrative burden placed on scientists, who spend far too much time writing reports on their activity, that of their own team, and of their UMR (“Unité Mixte de Recherche”; normally formed by at least a few teams); these reports then have to show how all this activity is coherent with a larger group and with research objectives that have been dictated from above, by various layers of ministries, agencies, and institutions. These reports, as well as grant requests are then evaluated by various agencies, too often only by French scientists, so a great deal of time is wasted in redundant evaluations that are not of optimal quality. The notoriously heavy French bureaucracy greatly hampers scientific progress by limiting initiative of scientists or by forcing them to change their research focus to follow various fashions that are dictated by institutions.