based on Indiana's Academic Standards, Science,
as adopted by the Indiana State Board of Education, Nov 2000.

numbers (K:, 1: to 8:) refer to the age-appropriate grade-level for the content.

Review

Arthropods (phylum Arthropoda)

grades K: to 3:

• Bugs are small animals
• with six or more legs
• external skeleton (made of fingernails)

Bugs (Insects) are one class of Arthropods

grades 4: to 8:

• animals with external skeleton
  • typically made of chiton (like finger nails)
  • segmented (like an earthworm)
• cold-blooded; multiple hearts; two "brains"
  • body brain - "just do it";
  • head brain - "just say no"
• development in leathery-shelled egg

Insects (class: Insecta):

grades 6: to college:

• head = several segments, brain
  • 2 antennae, 2 compound eyes, 3 pair mouthparts
• thorax = 3 segments; one ganglion (body brain)
  • 3 pair legs, 2 pair wings
• abdomen = up to 11 segments; each with ganglion (except last 1 or 2)
• earliest fossil (400 Myr BP) = cockroach-like
• Orders [examples]:
  • Odonata - dragonflies
  • Cursoria - cockroaches, walkingsticks
  • Orthoptera - grasshoppers
  • Hemiptera - true bugs
  • Hymenoptera - bees, ants, wasps
  • Coleptera - beetles
  • Lepidoptera - moths, butterflies
  • Diptera - flies

other Arthropod Classes

grades 6: to college:

millipeds (class Diplopoda)

• head: 2 short antennae, simple eyes, 2 pair mouthparts
• segmented abdomen; 2 pair legs per segment

centipeds (class Chilopoda)

• head: 2 long antennae, 2 compound eyes, 3 pair mouthparts
• segmented abdomen; 1 pair legs per segment
  • 1st segment has 1 pair poison claws pointed forward

shrimps, lobsters (crayfish), sowbugs (class Crustacea)

• head; 2 pair antennae, simple or compound eyes, 4 pair mouthparts
  • may be fused with thorax as cephalothorax
• thorax; 4-20 segments with 1 pair branched legs per segment
• abdomen; 1 - many segments with or without "legs"

spiders, ticks, mites (class Arachnoidea)

• cephalothorax; 2 pair mouthparts (poison fangs), 4 pair legs
• abdomen; 1 - many segments without "legs"
  • horseshoe crab subclass
  • spider subclass
    • scorpions (Order Scorpionida)
    • Daddy Longlegs, or harvestmen (Order Phalangida)
    • spiders, or Spider Old Woman (Order Araneae)
    • ticks & mites (Order Acarina)

Trilobites (class Trilobita)

Other phyla of lower animals

grades 6: to college:

Peripatus (class Onychophora)

• The missing link between worms and arthropods.

Earthworm (phylum Annelida)

Roundworm (phylum Aschelminthes)

Flatworm (phylum Platyhelminthes)

Jellyfish (phylum Cnidaria)

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