Tetrapulmonata Shultz, 1990 Superorder Serikodiastida Garwood & Dunlop, 2014 Order Araneida Clerck, 1757 - spiders Suborder Araneae Clerck, 1757 - tailless spiders Infraorder Opisthothelae Pocock, 1892 - unsegmented spiders Microorder Mygalomorpha Pocock, 1892 - mygalomorphs see [unranked] Mygalomorphae Pocock, 1892 1 Family †Fossilcalcaridae Wunderlich, 2015 2 Family Atypidae Thorell, 1870 - purse-web spiders