<P> With regard to living mammals, the more striking of Owen's contributions relate to the monotremes, marsupials and the anthropoid apes . He was also the first to recognize and name the two natural groups of typical Ungulate, the odd - toed (Perissodactyla) and the even - toed (Artiodactyla), while describing some fossil remains, in 1848 . Most of his writings on mammals, however, deal with extinct forms, to which his attention seems to have been first directed by the remarkable fossils collected by Charles Darwin, in South America . Toxodon, from the pampas, was then described and gave the earliest clear evidence of an extinct generalized hoof animal, a pachyderm with affinities to the Rodentia, Edentata and herbivorous Cetacea . Owen's interest in South American extinct mammals then led to the recognition of the giant armadillo, which he named Glyptodon (1839) and to classic memoirs on the giant ground - sloths, Mylodon (1842) and Megatherium (1860), besides other important contributions . Owen also first described the false killer whale in 1863 . </P> <P> At the same time, Sir Thomas Mitchell's discovery of fossil bones, in New South Wales, provided material for the first of Owen's long series of papers on the extinct mammals of Australia, which were eventually reprinted in book - form in 1877 . He discovered Diprotodon (1838) and Thylacoleo (1859), besides extinct kangaroos and wombats, of gigantic size . While occupied with so much material from abroad, Owen was also busily collecting facts for an exhaustive work on similar fossils from the British Isles and, in 1844--1846, he published his History of British Fossil Mammals and Birds, which was followed by many later memoirs, notably his Monograph of the Fossil Mammalia of the Mesozoic Formations (Palaeont . Soc., 1871). One of his latest publications was a little work entitled Antiquity of Man as deduced from the Discovery of a Human Skeleton during Excavations of the Docks at Tilbury (London, 1884). </P> <P> Following the voyage of the Beagle, Darwin had at his disposal a considerable collection of specimens and, on 29 October 1836, he was introduced by Charles Lyell to Owen, who agreed to work on fossil bones collected in South America . Owen's subsequent revelations, that the extinct giant creatures were rodents and sloths, showed that they were related to current species in the same locality, rather than being relatives of similarly sized creatures in Africa, as Darwin had originally thought . This was one of the many influences that led Darwin later to formulate his own ideas on the concept of natural selection . </P> <P> At this time, Owen talked of his theories, influenced by Johannes Peter Müller, that living matter had an "organising energy", a life - force that directed the growth of tissues and also determined the lifespan of the individual and of the species . Darwin was reticent about his own thoughts, understandably, when, on 19 December 1838, as secretary of the Geological Society of London, he saw Owen and his allies ridicule the Lamarckian' heresy' of Darwin's old tutor, Robert Edmund Grant . In 1841, when the recently married Darwin was ill, Owen was one of the few scientific friends to visit; however, Owen's opposition to any hint of transmutation made Darwin keep quiet about his hypothesis . </P>

Who invented the term dinosauria what was his idea about dinosaur metabolism