Arthro = Joint Pod = Foot Arthropods Arthro = Joint Pod = Foot
What do these animals have in common? Tough Exoskeleton (chitin – “ky- tin”) Jointed Appendages Segmented body
Why an exoskeleton? Protection Support Waterproof Flexible or Hard Added strength Anchor point Waterproof Prevents water loss
Challenges? Exoskeleton (armour) does not grow with the animal Rigid covering allows movement only at joints
Why jointed legs? Strong/light and adaptable Antennae, claws, legs, wings, flippers … evolve from the same jointed appendages
Why might several body segments help in evolution? Segmentation Why might several body segments help in evolution? Each repetitive segment can evolve a unique purpose!
Phylum Arthropoda Subphylum Uniramia Insects Chelicerates Crustaceans Centipedes & Millipedes Insects
Body Plan (insect)
Spider Body Plan
Crustacean Body Plan