origin of the tetrapods. He thus held, on the basis of detailed analyses of the snout and nasal capsule structures as well as the intermandibular, neuroepiphysial, and occipital regions, that Tetrapoda was biphyletic. In his view, the anatomical details of the Caudata (salamanders) bound them to the primitive porolepiform fishes, while all other tetrapods (“eutetrapods”) – apodans possibly excepted – were descended from primitive osteolepiforms. Thus Amphibia had arisen twice. On the basis of his findings, he argued that Amphibia should be split, with salamanders (and possibly caecilians) in one class (the Urodelomorpha), and the frogs as a separate class, the Batrachomorpha. The Lepospondyli was thought as possible Urodelomorphans, while the other Labyrinthodonts were thought to be Batracomorphs. Jarvik's ideas was never widely accepted, though Friedrich von Huene did include his system in systematic treatment of tetrapods. Few other supported his ideas, and today it has been abandoned by vertebrate paleontologists. The term "Batrachomorpha" is however sometimes used in a cladistic sense to denote Labyrinthodonts more closely related to modern amphibians than to amniotes. Lungfish phylogeny Jarvik also studied the anatomy and relationships of lungfish which he held to be relatively primitive gnathostomes, possibly related to holocephalans, and of acanthodians, which he considered to be elasmobranchs rather than osteichthyans. He made contributions to a number of classical problems in comparative anatomy, including the origin of the vertebrates the origin of the pectoral and pelvic girdles and paired fins, and the homologies of the frontal and parietal bones in fishes and tetrapods Finally, Jarvik investigated the anatomy of Ichthyostega, resulting in a monograph with an extensive photographic documentation of the material collected in 1929–1955. Legacy Some of Jarvik's views did not accord with general opinion in vertebrate paleontology. However, his anatomical studies of Eusthenopteron foordi laid the foundations for modern studies of the transition from fishes to tetrapods. Jarvik was a member of the Royal Swedish Academy of Sciences and French Academy of Sciences and Knight of the Order of Vasa. The lungfish Jarvikia and the osteolepiform Jarvikina are named after him. See also Hans C. Bjerring Tor Ørvig Gunnar Säve-Söderbergh Erik Stensiö References Selected publications Books Théories de l'évolution des vertébrés reconsidérées à la lumière des récentes découvertes sur les vertébrés inférieurs. Masson, Paris. 1960. Basic Structure and Evolution of Vertebrates, 2 Vols. Academic Press, London. 1980 External links An Obituary to Erik Jarvik Swedish paleontologists 20th-century Swedish zoologists Paleozoologists