Threatened arthropods United States, and IUCN Red List for international purposes. Only a tiny fraction of the planet's endangered arthropods are formally recognized as such, as no one has ever evaluated the conservation status of the vast majority of arthropod species. It is difficult to estimate the total number of endangered arthropod species, since many of the taxa themselves have not been recorded. For example, in North America the estimated number of insect species exceeds 163,000, of which only about two thirds are taxonomically known. An even greater discovery awaiting, over 72 percent of North American arachnids are yet to be named
Other Minds: The Octopus, the Sea, and the Deep Origins of Consciousness of the animals gather. Octopuses are, he notes, inquisitive, observant, even friendly, but the architecture of their nervous systems is entirely different from the vertebrate plan. The octopus's intelligence is distributed throughout its body: there are almost twice as many nerve cells in their eight muscular arms as in their brain. Intelligence is, Godfrey-Smith argues, predicated upon the "complex active bodies". Three groups of bilaterian animals with that kind of body plan evolved in the Cambrian period, some 500 million years ago: the arthropods (such as crabs and insects), the vertebrates, and within the molluscs, the cephalopods. Godfrey-Smith disagrees with