Given the following passage  "The leading naturalist in Britain was the anatomist Richard Owen, an idealist who had shifted to the view in the 1850s that the history of life was the gradual unfolding of a divine plan. Owen's review of the Origin in the April 1860 Edinburgh Review bitterly attacked Huxley, Hooker and Darwin, but also signalled acceptance of a kind of evolution as a teleological plan in a continuous "ordained becoming", with new species appearing by natural birth. Others that rejected natural selection, but supported "creation by birth", included the Duke of Argyll who explained beauty in plumage by design. Since 1858, Huxley had emphasised anatomical similarities between apes and humans, contesting Owen's view that humans were a separate sub-class. Their disagreement over human origins came to the fore at the British Association for the Advancement of Science meeting featuring the legendary 1860 Oxford evolution debate. In two years of acrimonious public dispute that Charles Kingsley satirised as the "Great Hippocampus Question" and parodied in The Water-Babies as the "great hippopotamus test", Huxley showed that Owen was incorrect in asserting that ape brains lacked a structure present in human brains. Others, including Charles Lyell and Alfred Russel Wallace, thought that humans shared a common ancestor with apes, but higher mental faculties could not have evolved through a purely material process. Darwin published his own explanation in the Descent of Man (1871).",  answer the following question. Note that the answer is present within the text.  Question: What rank was Owen at what he did?
A:
leading