Opisthosoma

• Chelicerata
• Opiliones
• Pecten (biology)
• Scorpion
• Spinneret (spider)
• abdomen
• arachnid
• arthropod
• book gill
• book gills
• book lung
• book lungs
• heart
• horseshoe crab
• prosoma
• spider
• whip scorpion
• whip spider