Threatened arthropods and described. The total number of living arthropod species is probably in the tens of millions. One conservative estimate puts the number of arthropod species in tropical forests alone at six to nine million species. As a consequence of all of the above, most published estimates of the total number of endangered insects and arachnids are probably low by at least an order of magnitude. Conservatively at least eighty percent of all living animal species are arthropods. Since arthropods constitute the majority of the faunal biomass on Earth, their role is vital to the survival of large numbers of insectivores
Threatened arthropods of endangerment beyond the amount of land consumed by the fragmenting agent. As an example, consider the construction of a highway, whose width is an effective barrier to arthropod migration. Many arthropods never migrate more than about 200 feet from their place of birth, so a freeway or dual carriageway effectively fragments many arthropod colonies such that they cannot interact. Studies have shown the greater vulnerability to extinction where habitats are fragmented. The following is a very small fraction of the potentially hundreds of thousands of endangered arthropods, limited to species which have been formally recognized as to their special