Dichotomous Key/Arachnida

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[edit] 1

• Pedipalps
  • Specialized claws - 2
  • Other formation - 3

[edit] 2

• Abdomen
  • extends into tail and stinger - Scorpionida
  • Short and rounded at rear - Pseudoscorpionida

[edit] 3

• Chelicerae
  • Large, formed of two articles covered with teeth - Solifugae
  • Other formation - 4

[edit] 4

• Pedipalpi
  • Chelate - 5
  • Unchelate - 6

[edit] 5

• First leg pair
  • Modified into sensory organs - 9
  • Used for walking - 8

[edit] 6

• Prosoma and opisthosoma
  • Joined - Opiliones
  • Separate - 7

[edit] 7

• Eyes
  • Present - Araneae
  • Not present - Palpigradi

[edit] 8

• Raisable and lowerable hood that covers eyes and chelicerae
  • Present - Ricinulei
  • Not present - Acari

[edit] 9

• Cephalothorax
  • Divided into two plates - Schizomida
  • Undivided - 10

[edit] 10

• Telson
  • Present - Uropygi
  • Not present - Amblypygi