Opisthothelae is a taxon within Order Araneae, consisting of the Mygalomorphae and the Araneomorphae, but excluding the Mesothelae. Opisthothelae is sometimes presented as an unranked clade and sometimes as a suborder of the Araneae. In the latter case, Mygalomorphae and Araneomorphae are demoted to infraorders. The fairly recent creation of this ...