1. It All Begins 530 Million Years Ago….
with Jawless Fish
Swims Side to Side Motion
Tiny Armor plates cover body
Wide set eyes
Has a BACKBONE!

2. Kingdom Animalia
Phylum: Chordata

3. Phylum: Chordata – members called chordates
All have slits in throat area at some point.
All have a backbone OR a notochord to support body
(A notochord is a flexible rod)
All have a nerve cord running down the back
What is this nerve cord in humans?
SPINAL CORD
MOST are vertebrates
The ancient jawless fish is part of a phylum called Chordata.
All members in chordata are called Chordates.

4. Notochord- found in embryo stage of all chordates & some adults

5. Gill Slits in all Chordates

6. MAJOR GROUPS OF CHORDATA
FISHES
AMPHIBIANS
REPTILES
BIRDS
MAMMALS

7. Most Chordates are Vertebrates
VERTEBRATES ARE A SUBPHYLUM OF CHORDATES
A Vertebrate has a BACKBONE that is part of an internal skeleton
Another name for backbone is SPINE
Internal skeleton is called an ENDOSKELETON
Other Animals, like insects have EXOSKELETON

8. Most Chordates are Vertebrates
Backbone is made of many VERTEBRAE or bones lined up in a row with flexible joints
Each vertebra has a HOLE that allows SPINAL CORD/NERVE CORD to pass through

9. INTERNAL SKELETON:ENDOSKELETON
Backbone is only part of endoskeleton
Also includes: SKULL & RIBS, ARM & LEG BONES (if present)

10. FUNCTIONS OF ENDOSKELETON
Protect internal organs
Give body shape & support
Give muscles a place to attach

11. OTHER CHARACTERISTICS:
Endoskeleton grows with the animal – doesn’t have to be replaced like an exoskeleton
ADVANTAGE! Animal can grow BIGGER than animals with either an exoskeleton or no skeleton

12. CONTROLLING BODY TEMPERATURE:
There are 2 types of Vertebrates in relation to controlling body temperature:
1. Ectotherms
2. Endotherms

13. An animal whose body DOES NOT produce much INTERNAL heat
ECTOTHERMS:
An animal whose body DOES NOT produce much INTERNAL heat
Body temperature changes with the temperature of their environment
Sometimes called COLDBLOODED
Misnomer – sometimes blood is quite warm!
Includes: fish, amphibians & reptiles

14. Ectotherms

15. Includes: Birds & Mammals
ENDOTHERMS
An animal whose body regulates its own body temperature no matter what the temperature of the environment.
ADAPTATIONS:
Sweat glands
Fur
Hair
Feathers
Includes: Birds & Mammals

16. Advantage: https://www.youtube.com/watch?v=LH1p1XOqfsg
Endotherms can live in a greater variety of environments than ectotherms
Why?
Because they can take steps to keep their body temperature stable. Ectotherms are dependent on environment.
ASSIGNMENT: Read Summary & Complete Review & Reinforce.