1. Phylum Chordata

2. Characteristics of all chordates Dorsal, hollow nerve cord Post-anal tail Gill pouches at some time in the live Notochord The most complex of the animals Most, but not all, have backbones

3. Characteristics  Notochord Longitudinal flexible rod of cartilage located between gut and dorsal nerve cord Persists into adulthood in some chordates In many it is replaced by vertebral column Spongy material between vertebral bones is remnant of notochord

4. Characteristics  Dorsal Hollow Nerve Cord In embryo, formed from a plate of dorsal ectoderm that rolls up into a tube Located dorsal to notochord Unique due to its hollow structure Develops into chordate’s central nervous system

5. Characteristics  Pharyngeal Gill Slits Openings of the upper digestive tube in chordates Pharynx is area just behind mouth During embryonic stage of chordates these slits connect the outside to the pharynx Early chordates used them as devices for filter feeding Evolved and became modified to function in gas exchange

6. Characteristics  Post Anal Tail Most chordates have tail extending beyond the anus Many aquatic species have tail equipped with skeletal and muscular tissue for movement.

7. Taxonomy of Chordates Taxonomy- the study of classification

8. Phylum Chordata Subphylum Urochordata Subphylum Cephalochordata Subphylum Vertebrata Superclass Fishes Class Agnatha Class Chondrichthyes Class Osteichthyes Class Amphibia Class Reptilia Class Aves Class Mammalia

9. Subphylum Urochordata  Tunicate-sea squirt are most popular example for study  Larva has all four chordate characteristics  Retain only gill slits in adult Most are marine No backbone

10. Subphylum Cephalochordata  Small marine animals just a few cm. long  Lancelets-blade shape  All four chordate characteristics persist in adult  No backbone

11. Subphylum Vertebrata  Additionally, they demonstrate Cephalization Vertebral column (backbone) as part of endoskeleton Closed circulatory System Show all four chordate characteristics at some time in their life.

12. Superclass Fish  Characteristics- Primitive No jaws Cartilaginous skeleton Scaleless skin Oral sucker in place of jaws Predators and filter feeders Anticoagulating saliva Fresh and salt water  Examples Lamprey hagfish Class Agnatha

13. Class Chondrichthyes  Cartilaginous skeleton  Skin covered with denticles, not scales  Five to seven gill slits per side  No swim bladder  Internal fertilization  Spiral valve intestines  Five to seven gill arches Examples: sharks rays

14. Class Osteichthyes Bony Fish  Largest group of vertebrates  Calcified skeleton  Great maneuverability  Swim bladder for control of buoyancy

15. Class Amphibia  Eggs are hatched in water and lack shell.  First part of life is water and then move to land.  Name means “two lives”  Examples: Frogs, toads Newts, salamanders, necturus Legless, burrowing amphibians

16. Class Reptilia  First true “land animal”  Amniote egg with shell  Scaly skin too thick for respiration  Formerly 16 orders  4 orders remain turtles, tortoises alligators, crocodiles lizards, snakes tuatara

17. Class Aves  Warm blooded  Keel shaped breast bone in birds that fly  Hollow bones  Characterized by: beaks, wings, feathers

18. Class Mammalia  Mammary glands to feed young  Hair  Differentiated teeth  Most give live birth  Warm blooded  Sub-cutaneous fat  Most have larger brains than other vertebrates of their size.

19. Monotreme Mammals  Only in Australia and New Guinea  Hair and mammary glands  No nipples  Reptilian egg  Only examples: platypus echidna

20. Echidna

21. Marsupial Mammals  Embryos born early and complete development in pouch  Examples: opossum kangaroo bandicoot koala

22. Placental Mammals  Young develop in uterus  Joined to mother by placenta

23. Examples- Placental Mammals  Edentata- Toothless Lagomorpha

24.  Insectivora Chiroptera Primate

25. Rodentia Carnivora Artiodactyla Perissodactyla

26. Proboscidea Sirenia Cetacea