(b. Caen, France, 10 August 1914; d. Paris, France, 26 February 1981)
Jean-Pierre was the second child of Madeleine Auvray and Gaston Lehman, a civil engineer descended from old Parisian stock. He studied at the Lycée Carnot, and later at the Sorbonne, then the seat of the Faculty of Sciences, escaping for only a year to Grenoble, where chemistry instruction (then required for a licence in natural sciences) was of a higher standard. In Geronble he met Ingegärd Enesyröm, a swedish doctor’s daughter, who was finishing her higher education in French. They married and lived in Paris most of their lives, with an annual trip to Sweden; they had one son and two daughters. Although educated as a Catholic, Lehman professed a serene atheism. He was an officer of the Légion d’ honneur and of the Plames académiques and was elected in 1979 to the Académic des sciences.
Lehman taught at the Lycée de Nice from 1940 to 1945, then at the Laboratoire de géologie de la faculté des sciences de Paris from 1950 to 1955, and finally at the Ècole normal supérieure de Saint-Cloud and the Muséum national d’historie naturelle, as the holder of the chair in paleontology, from 1956 to 1981. He attracted a large number of students and founded a school of paleoanatomy that soon became officially recognized as the Institut de paléonatologie, now one of the world’s most important centers of paleontology. He also organized international colloquia (1961, 1966, 1973), gave conferences in many foreign countries, and served as secretary, then vice president, of the Société géologique de France. His tireless efforts in promoting the cause of paleontology led him to become editor of the journal Les annales de paléontologie, then to the the Cahiers de paléontologie, where several of his disciples have published anatomical monographs. He was also a member of the scientific committee of the Fondation Singer Polignac, which published, thanks to his influence, several paleontological works.
Lehman contributed to the Traité de zoologie of P. P. Grassé (vol. XIII, fasc. 3) and the Traité de paléontologie of Jean Piveteau (vols. III, IV, and V). He translated many paleontological works from Swedish, German, and English. Not content to publish in his specialized field of research alone, he addressed the major problems of paleontology and evolution in four thoughtful books and many papers. Finally, he oversaw the renovation of the Galerie de paléontologie, established the Galerie de paléobotanique, and organized public paleontological exhibitions in the Parc de Vincennes and in the museum.
The driving power behind all these activities was Lehman’s tenactiy and enthusiasm for research. His Diplôme d’études supérieures (1937), a prelude to the Agrégation degree (1939), influenced his whole career: it concerned the fishes of the Upper Devonian of Scania and was prepared at the Museum of Natural History of Stockholm. He later dedicated all his scientific activity to the study of lower vertebrates and to work directly or indirectly carried out with the Swedish team; Erik A. Stensiö had made stockholm the heart of such research. Lehman began with a study of Agnatha (jawless vertebrates), and the knowledge he acquired on this group allowed him later to discuss the problem of the origin of vertebrates. But very rapidly the fish of North Africa and Madagascar became a main focus of his research, with the material coming essentially from his own excavations (in 1950, 1952, 1954, 1961, 1964, 1966, 1969, 1974, and 1979). His 1969 expedition to Spitzbergen, for which he obtained much financial and material support, produced twenty-three tons of fossils that are still under study. The Arthrodires from the Upper Devonian of Morocco were known previously only by isolated plates. Lehman’s new material brought not only the knowledge of new taxa of giant size, but also that of the endocranium, the thoracic shield, and the hear-thorax link.
On the other hand, the presence in Africa of species of an otherwise American genus allowed him to draw paleogeographic conclusions. The Actinopterygians from Madagascar (Paleonisciformes, Parasemionotiformes) were the subject of his doctoral thesis. Before his studies, reconstructions of the endocranium were rare; he made some with such great precision that they are now “better known than those of many genera of extant Teleostomes. He also followed the evolution of the dermal cephalic skeleton, showing that bone fusions or dissociations are frequent in Actinopterygians. He confirmed moreover the morphogenetic role of the pit lines and established the precocity of bone regression in these fishes. Finally he showed that the Actinopterygian Cheirolepis was not an intermediate form between Crossopterygians and Actinopterygians and that “Chondrichthyens” and “Holosteens” were not valid systematic units. Lehman was still studying Actinopterygian fishes when he died.
For the Crossopterygians and Dipnoans, Lehman used the same methodology: the search for fossils, careful anatomical study, establishment of bone homologies (for example, between the squamosal of Crossopterygians and the propercular of Actinopterygians), and phyletic considerations (for example, the heterogeneity of the Crossopterygians, the origin of Urodeles).
The Triassic stegocephalians constitute the second center of his research. Those from Madagascar had rarely been studied. After finding well-preserved skulls of néorachitomes, bentosuchids, rhinosuchoids, and Trematosauria, he described them, followed growth series, and recognized new taxa, including the most ancient members of the Brachypodoids. The presence of freshwater Bentosuchids in marine formations led him to reconstruct local paleoecology and to recognize continental relations between Madagascar and the Northern Hemisphere in the Eotriassic, as well as a separation between Madagascar and Africa as early as that epoch. Concerning the Moroccan stegocephalians, they were virtually unknown until the work of Lehman. They appear to be quite varied, but their study mainly demonstrated the insufficient systematic value of the vertebral criterion in Stegocephalia; the existence of two separate lineages, batracomorphs and reptiliomorphs; the evolution of the otic notch in this group; and the state of specialization of Embolomers. It also clarified the composition of the Ichthyostegalia.
These numerous and various analyses were underlined by Lehman’s constant preoccupation “to consider each fossil as a vestige of a once living animal” and “to revive these ancient groups whose comparison with extant forms gives less evident results than do Tertiary vertebrates.” Lehman was one of the first paleontologists to examine lower vertebrates from a functional as well as an anatomical point of view, relying heavily on comparative anatomy.
I. Original Works. “Etude complémentaire des poissons de l’Eotrias de Madagascar,” in Kungl. Svenska Vetenskapsak. Handlingar, 4th ser., 2 , no. 6 (1952); “Généralités sur les amphibiens: Les emboloméres et les seymouriamorphes, Les rachitomes, Les phyllospondyles,” in Jean Piveteau, ed., Traité de paléontologie, V (Paris, 1952–), 3–52, 67–125, 173–224, 227–249; “Les arthrodires du Dévonien supérieur du Tafilalet,” in Notes et mémoires, serv, géol, Maroe (Rabat, 1956), 1–70; “Compléments á l’étude des genres Escrinesomus et Bobasatrania,” in Annales de paléontologie, 42 (1956), 1–28; “Sous classe des actinoptergii; Généralités et évolution, superordre des chondrostéens,” in Pierre Paul Grassé, ed., Traité de zoologie, XIII, fasc. 3 (Paris); L’évolution des vertébrés inférieurs (Paris, 1959); “Les dipneustes du Dévonien supérieur du Groenland,” in Meddelelser om Grönland, 160 (1959); “Les stégocéphales du Trias de Madagascar,” in Annales de paléontologie, 47 (1962).
“Actinopterygii, dipnoi et crossopterygii, brachiopterygii,” in Jean Piveteau, ed., Traité de paléontologie, IV, fasc. 3 (Paris, 1952–); “Nouveaux stégocéphales de Madagascar,” in Annales de paléontologie (vertébrés), 52 , fasc. 2 (1966), 117–139: Précis de géologie, 2 vols. (Paris, 1967–1968), written with Jean Auboin and P. Brousse; “Nouveaux vertébreés fossiles du Trias de la série de Zarzaitine,” in Annales de paléontologie (vertébreés), 57 , fasc. 1 (1971), 71–93; “Quelques réflexions sur la phylogénése des vertébrés inférieurs,” in Colloque Internat, du CNRS, no. 218 (1975); “Nouveaux poissons fossiles du Dévonien du Maroc,” in Annales de paléontologie (vertébrés)62 fasc, 1 (1976), 1–34 Les preuves paléontologiques de l’évolution (Paris, 1973), trans, by Patricia Crampton as The Proofs of Evolution (New York and London, 1977); “Nouveaux trématosaures de Madagascar: Les stégocéphales malgaches et leur paléoécologie,” in Annales de paléontologie (verteébrés), 65 , fasc. 1 (1979), 35–54.
II. Secondary Literature. For obituaries, see Z. Rocek, Vesmir, prirod, Casopsis Ceskosl, Akad, Ved., 60 , no. 3 (1981), 272; and Donald and Denise Russell, News Bulletin of the Society of Vertebrate Paleontologists, 122 (1981), 65–66.