Arthropod classification

Arthropod classification

1. Arthropod classification

2. Subphylum trilobitomorpha Trilobites Diverse group of marine invertebrates who lived during the 500 -250 million years ago. Well preserved fossil record . ( Why ?) Ancestor to modern arthropods

3. Trilobites are extinct, hard-shelled animals that lived in the seas millions of years ago. They evolved at the beginning of the Paleozoic Era (over 500 million years ago) and went extinct during the late Permian period (248 million years ago). The Cambrian Period is known as "The Age of Trilobites." Trilobites were very common and very diverse; over 15,000 species of trilobites are known. Some trilobites crawled along the sea floor, some swam, and others drifted with ocean currents. The different trilobite species probably had different diets; some were herbivores (eating plants), some were detrivores (eating decayed material) and some were scavengers (eating carrion). Anatomy : Trilobites were marine invertebrates that had hard, three-lobed shells (the axial lobe and two pleural lobes), hence the name "trilobite". The body is divided into three parts, the cephalon (head), the segmented thorax, and the pygidium (tail piece). These arthropods had jointed legs, compound eyes, and antennae. They ranged in size from less than 1/4 inch (0.6 cm) to over 2 feet (0.6 m) long. Protection : Many trilobites had protective spines. Some could roll up into a ball, and some could burrow into the sea floor.

4. Subphylum CHELICERATA Class Merostomata – Horseshoe Crabs Class Arachnida – Spiders, Scorpions, Ticks Class Pycnogonida – Sea Spiders

5. Subphylum chelicerata No antenna Two body segments (cephalothorax, abdomen) First pair of appendages (chelicera) adapted for feeding Second pair of appendages ( pedipalps ) to hold prey Book lungs/book gills for respiration Four pairs of walking legs

6. Subphylum mandibulata Class Myriapoda Order Chilopoda (Centipedes) Order Diplopoda (Millipedes) Class Insecta Subclass Apterygota (Wingless Insects) Subclass Pterygota (Winged Insects) Class Crustacea Subclass Malacostraca (Crabs, Lobsters, Shrimp, Woodbugs ) Subclass Cirripedia (Barnacles) Subclasses Ostracoda , Copepod (Planktonic Crustaceans)

7. Subphylum mandibulata Head appendages are modified as mandibles for chewing or grinding. Class Myriapoda Order Chilopoda (Centipedes) One pair of walking legs per segment Flat body, fast moving Some poisonous Carnivores Order Diplopoda (Millipedes) Two pairs of walking legs per segment Round body, slow movers Herbivores

8. Subphylum mandibulata Class Insecta Three pairs of walking legs (uniramous)on thorax One pair or antenna Three body segments May have wings (only flying invertebrates)

9. Mosquito

10. Subphylum mandibulata Class Myriapoda Order Chilopoda (Centipedes) Order Diplopoda (Millipedes) Class Insecta Subclass Apterygota (Wingless Insects) Subclass Pterygota (Winged Insects) Class Crustacea Subclass Malacostraca (Crabs, Lobsters, Shrimp, Woodbugs ) Subclass Cirripedia (Barnacles) Subclasses Ostracoda , Copepod (Planktonic Crustaceans)

11. Subphylum mandibulata Class Crustacea Two or three body segments 4-5 pairs of walking legs 2 pairs of antenna

12. Barnacles