Class Arachnida
Subclass Arachnida
Order Palpigrada
Order Haptopoda (extinct)
Order Trigonotarbida (extinct)
Order Aranae
Order Amblypygida
Order Schizomida
Order Ricinulei
Order Acari
Subclass Dromopoda
Order Phalangiotarbida (extinct)
Order Opiliones
Order Scorpianes
Order Pseudoscorpionida
Order Solifugida