(Holothyrida) (Holothyrida) is a biological order of the phylum Arthropoda (Arthropods) and class Arachnida (Arachnids).
Allothyridae
Holothyridae
Neothyridae
Opiliones
Holothyrida
Ixodida
Mesostigmata
Palpigradi
Opilioacarida
Pseudoscorpiones
Ricinulei
Sarcoptiformes
Scorpiones
Schizomida
Araneae
Solifugae
Trombidiformes
Uropygi
Amblypygi