Spiders

Spiders (order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except Antarctica, and have become established in nearly every land habitat. , 53,680 spider species in 139 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifica

Opisthothelae is a suborder of spiders within the order Araneae, containing Mygalomorphae and Araneomorphae, but excluding Mesothelae. The Opisthothelae are sometimes presented as an unranked clade and sometimes as a suborder of Araneae. In the latter case, Mygalomorphae and Araneomorphae are treated as infraorders.

taxonomic database

animals evolving to resemble ants

science of naming, defining and classifying spiders

origin from a chelicerate ancestor and diversification of spiders through geologic time

Spiders that form long-lasting aggregations