Include: 

• Class Chelicerata;
•     Subclass Arachnida - spiders, scorpions, mites
• Class Myriapoda
•     Subclass Chilopoda - centipedes
•     Subclass Diplopoda - millipedes
•     Subclass Symphyla - symphylans
•     Subclass Pauropoda - paoropodans
• Class Insecta
•     Subclass Oligoentomata - collembola

1. Bilaterally symetrical, triploblastic
2. Body segmented
3. Regional body specialization
4. Cuticle forms well-developed exoskeleton
5. In primitive forms, each true body segment with paired jointed appendages
6. Usually with paired compound eyes and one to several simple eyes
7. Coelom reduced to portions of the reproductive and excretory systems; main body cavity is an open hemocoel
8. Circulatory system open; dorsal heart is a muscular pump with ostia for blood return
9. Gut complete, with well-developed stomodeum and proctodeaum
10. Nervous system with dorsal ganglion, ventral nerve chords and circumenteric connectives
11. Cuticle molted during growth
12. Muscles striated and arranged in isolated segmental bands
13. Sexes usually separate

Oligoentomata - collembola

Return to Life Kingdoms Menu