Are spiders animals?

Spider. Spiders (order Araneae) are air-breathing arthropods that have eight legs and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other orders of organisms. read more

Spider-like arachnids with silk-producing spigots appeared in the Devonian period about , but these animals apparently lacked spinnerets. True spiders have been found in Carboniferous rocks from , and are very similar to the most primitive surviving suborder, the Mesothelae. read more