Spider taxonomy  Spider taxonomy is that part of taxonomy that is concerned with the science of naming, defining and classifying all spiders, members of the Araneae order of the arthropod class Arachnida with about 46,000 described species. However, there are likely many species that have escaped the human eye to this day, and many specimens stored in collections waiting to be described and classified. It is estimated that only one third to one half of the total number of existing species have been described. Arachnologists currently divide spiders into two suborders with about 114 families. Due to constant research, with new species being discovered every month and others being recognized as synonyms, the number of species in the families is bound to change and can never reflect the present status with total accuracy. Nevertheless, the species numbers given here are useful as a guideline – see the table of families at the end of the article. Spider taxonomy can be traced to the work of Swedish naturalist Carl Alexander Clerck, who in 1757 published the first binomial scientific names of some 67 spiders species in his "Svenska Spindlar" ("Swedish Spiders"), one year before Linnaeus named over 30 spiders in his "Systema Naturae". In the ensuing 250 years, thousands more species have been described by researchers around the world, yet only a dozen taxonomists are responsible for more than a third of all species described. The most prolific authors include Eugène Simon of France, Norman Platnick and Herbert Walter Levi of the United States, Embrik Strand of Norway, and Tamerlan Thorell of Sweden, each having described well over 1,000 species. At the very top level, there is broad agreement on the phylogeny and hence classification of spiders, which is summarized in the cladogram below. The three main clades into which spiders are divided are shown in bold; , they are usually treated as one suborder, Mesothelae, and two infraorders, Mygalomorphae and Araneomorphae, grouped into the suborder Opisthothelae. The Mesothelae, with only 9 species, make up an insignificant proportion of the total of around 45,000 known species. Mygalomorphae species comprise around 6% of the total, the remaining 94% being in the Araneomorphae. The Araneomorphae are divided into two main groups: the Haplogynae and the Entelegynae. The Haplogynae make up about 10% of the total number of spider species, the Entelegynae about 83%.