Arthropod phylogeny & Insect Evolution

1. Arthropod phylogeny & Insect Evolution

2. Objectives: Identify characteristics of the Arthropoda Discuss Arthropod Phylogeny Characteristics of major taxa Discuss Insect Evolution

3. Arthropoda Arthro- Refers to Joints Poda- Refers to feet

4. Arthropoda Characteristics • Paired, jointed appendages • Segmented body plan • Land forms have tracheae or book lungs, • Aquatic forms have gills

5. Arthropoda Characteristics • Compound eyes • Open circulatory system • Digestive system is a tube • Nervous system with brain, paired ventral nerve cords

6. Arthropoda • Exoskeleton is molted

7. Arthropoda

8. Arthropoda • Evolved from Annelida

9. Ecdysozoans

10. Arthropoda Phylogeny • Many hypotheses exist • Molecular data suggest:

11. Arthropoda Classification Chelicerata Mandibulata Hexapoda = antennae

12. Arthropoda Classification • Chelicerae = feeding appendages = fangs in spiders

13. Arthropoda Classification 1. Chelicerata Classes: Merostomata - horseshoe crabs Arachnida - spiders, scorpions, ticks, mites

14. Arthropoda Classification Chelicerata • Mainly terrestrial • Body Divisions - Cephalothorax, abdomen • No antennae • No chewing mandibles

15. Arthropoda Classification Chelicerata • First and second pair of appendages - chelicerae, pedipalps used for manipulation of food, locomotion, defense, copulation • Next four pair of appendages - walking

16. Arthropoda Classification Crustacea • Aquatic • Body divisions - cephalothorax and abdomen • Gills • 2 pairs antennae - touch and taste • Biramous appendages - two jointed branches arising from their base

17. - biramous appendages

18. Arthropoda Classification Crustacea • Mandibles and maxillae used for feeding • Chelipeds on lobsters and crayfish - pinching claws • Larval stage • Green glands

19. Arthropoda Classification Hexapoda Class: Insecta - insects

20. Arthropoda Classification Insecta characteristics Terrestrial and some aquatic Body plan - Head, thorax, abdomen Uniramous 1 pair antennae 3 pairs legs on thorax Malpighian tubules

21. Insect Evolution • Four stages of insect evolution: • Development of insect body form • Development of wings • Development of wing flexion • Development of complete metamorphosis

26. Orders: Ephemeroptera = ?

27. Odonata = ?

28. Plecoptera

29. Megaloptera

30. Coleoptera

31. Lepidoptera

32. Diptera