OWEN, RICHARD (b. Lancaster, England, 20 July 1804; d. Richmond Park, London, England, 18 December 1892), comparative anatomy, vertebrate paleontology, geology.

    conclusion of which contains some of Owen's views on Darwin's hypothesis. All of these works were based on the prodigious amount of dissection and observation performed by Owen in preparing the five-volume Descriptive and Illustrative Catalogue of the Physiological Series of Comparative Anatomy of the Royal College of Surgeons' Museum, of his nearly twenty courses of Hunterian lectures, and of his many research papers.

Owen's paleontological work began in 1837 with Darwin's South American fossils and especially with the monograph on the Toxodon that Owen recognized as an intermediate type, with anatomical characteristics normally identified with rodents, cetaceans, and pachyderms. His works on Darwin's other fossils, for example, Glyptodon and Macrauchenia, are no less important. Owen also published on the marsupial characteristics of a group of fossils from the Stonesfield Slate (1838) and the first part of his major Report on British Fossil Reptiles to the British Association (1839, part two in 1841). This two-part Report was the framework on which Owen developed his exhaustive four-volume History of British Fossil Reptiles (1849-1884), which is a separate publication of his collected papers issued principally by the Palaeontographical Society. Also in 1839 Owen received a fragment of a femur from New Zealand, which he identified as belonging to a previously unknown giant terrestrial bird. This first paper on the New Zealand moa developed into a major series of publications on Dinornis and similar flightless birds. In addition, Owen paid particular attention to fossils from South Africa and Australia, the latter in relation to his interest in marsupials, and published many new species and new descriptions of these faunae. Also of interest are his 1842 studies of English Triassic labyrinthodonts and his description of the Jurassic bird Archaeopteryx (1863).

Despite the quantity of Owen's paleontological work before 1856, his career can be divided in two segments, not only by his place of employment but also by the different emphases of his work. While at the College of Surgeons the principal thrust of his work, and also of that museum's collections, was comparative-anatomical. After his transfer to the British Museum with its rich collections of fossils, which Owen further enriched, he naturally changed the emphasis of his work to paleontology. One aspect of this changed emphasis was his series of lecture courses on paleontology at the Royal School of Mines beginning in 1857; they were well-received and later compiled in his popular text Paleontology (1860).

Owen made a number of contributions to taxonomy, often modifying and clarifying one or another taxon in the course of his anatomical investigations and in describing many previously unknown species and genera. An excellent example of this work is his recognition of the marsupials as a natural, geographically defined group. Owen did undertake a classification of the Mammalia, in his Rede lecture in May 1859, in which he gave primal import to certain characteristics of the cerebral hemispheres. By these criteria he divided the Mammalia into four subclasses of equivalent value: Lyencephala, Lissencephala, Gyrencephala, and Archencephala (in order of increasing complexity). A strength of Owen's classification was the close association of the monotremes and marsupials in his Lyencephala. The other three subclasses graded imperceptibly into one another. The Archencephala, moreover, contained just one species, man. Owen believed that his cerebral criteria--anterior and posterior extension of the cerebral hemispheres, the posterior horn of the lateral ventricle, and the presence of a hippocampus minor--separated man further from the anthropoid apes than the latter were separated from the most primitive primates.

Owen's views on the transmutation of species are not entirely clear, partly on account of his writing style. In 1848 he claimed to have no idea of what the secondary causes may have been by which the Creator introduced new species, and he refrained from publishing on the subject. He did think that there were six possible ways in which the Creator might have acted but would not enumerate them. This, of course, was soon after the publication of Chambers' Vestiges of the Natural History of Creation, a much talked-about book. He had no objection to the notion that the Creator may have worked through secondary causes and recognized that, among animals, there had been an ascent and progression. Owen responded very vigorously to Darwin's Origin in a long, anonymous attack in the Edinburgh Review for April 1860. He was totally unable to accept the possibility that selective action of external circumstances might cause new species to arise. He observed that no effects of any of the hypothetical transmuting influences had been recorded. His objections were not to evolution's having occurred but rather that Darwin's mechanism, natural selection, had not been demonstrated as adequate. He thought “an innate tendency to deviate from parental type” the most probable way that secondary causes have produced one species from another (On the Anatomy and Physiology of the Vertebrates, III, p. 807).

The basic ideas Owen put forth in his Rede lecture had been presented previously in London meetings, one of which T. H. Huxley attended. Huxley doubted the validity of Owen's subclass Archencephala,