Tooth Types

• Examine the teeth in the shark jaw.– Where do the teeth grow?– Compare the shark teeth to the

slide of placoid scales.

• View the drawings of acrodont, pleurodont and thecodont teeth.– How does tooth structure relate to

an animals method of eating?

1 Placoid Scales2 Teeth3 Mouth

Modified Scales

Chondrichthyes

Acrodont

Some Osteichthyes

Pleurodont

AmphibiansReptiles

Thecodont

CrocodiliansMammals

Some Osteichthyes

Molar Structure

• Examine the drawings of secodont and selenodont teeth and compare them to the teeth found in the dog/cat and deer skulls.– Which has secodont teeth?

Selenodont?– How are secodont and selenodont

teeth used?

Selenodont Molars

Ruminants

Pink – enamel ridge

Secodont Molars

Carnivores

Tooth Pattern

• Identify the following tooth types in the deer, dog/cat and rat jaws.– Incisors– Canines– Premolars– Molars

• Which teeth are missing in the deer? Rat? Why?

• How are the dog/cat premolars structured for eating meat?

Tooth Pattern

Rodent

I IncisorsC CanineP PremolarM Molar

I

Tooth Pattern

Ruminant

I IncisorsC CanineP PremolarM Molar

Tooth Pattern

Carnivore

I IncisorsC CanineP PremolarM Molar

Skull Structure

• Anapsids are ancestral to both diapsids and synapsids.

• Locate the temporal openings on the skulls before you.

Skull Structure

Anapsid

Lacks temporal opening

Example: Turtles

Skull Structure

Synapsid

PelycosaurExtinct mammal ancestors

Modern Mammals

Single Temporal Opening

Skull Structure

Diapsid

Two Temporal Openings

1

2

1

2

Examples: Reptiles, Birds, Crocodiles

Rib Cage

• Compare the ribcage of the pigeon, rat and frog.– How do the differences in their

ribcages relate to locomotion?– How do the differences in their

ribcages relate to the way they breath?

Forelimbs

• Identify the following on the frog, bird and cat skeletons.– Humerus– Radius– Ulna– Carpals– Metacarpals– Phalanges

• How do the structures above differ among the organisms?

Circulatory System• Compare the blood flow through a two,

three and four chambered heart.• Identify the chambers of each heart.• Which diagram best describes the blood

flow through and amphibian larva?• Vertebrates with three chambered hearts

evolved partitions in the ventricle and in a structure called the conus arteriosus to help keep oxygenated blood separate from deoxygenated blood. See drawing.

Evolution of Blood Circulation

Fish

Evolution of Blood Circulation

LungfishGill-Breathing Amphibians

Evolution of Blood Circulation

Conus Arteriosus of Frog

LARA

V

Evolution of Blood Circulation

CrocodiliansBirds

Mammals

Digestive Tracts

• Why does the shark lack a large intestine?

• Describe structures that increase surface area in the shark and pig intestine? How are they different/same?

• Why does the frog need much less surface area in its intestine compared with the shark and pig?

Pig Digestive Tract

Frog Digestive Tract

Shark Digestive Tract

Digestive Tract Key

1. Esophagus

2. Stomach

3. Duodenum

4. Intestine

5. Small Intestine

6. Large Intestine

7. Colon

8. Rectum

IC Cecum

IL Ileum

P Pyloric Sphincter

Brain Structure• Look at the figures of the brain and note

the relative size of each of the labeled regions.

– Which organism uses sight as its primary sense?

– Which organism uses smell as its primary sense?

– The mammal and the bird cerebellum are proportionally about the same size. However, the mammal’s cerebellum is more convoluted. How does this make their cerebellums different?

• Look at the wet mount of vertebrate brains.

– What region of the cat brain is much larger than the rest of the organisms?

– What is the purpose of the enlarged region?

– What is the purpose of the convolutions?

Brain Structure

Bird

Olfactory Lobe

Optic Tectum

CerebellumCerebrum

Medulla

Brain Structure

Mammal

Olfactory Lobe

Optic Tectum

Cerebrum

Cerebellum

Medulla

Brain Structure

Amphibian

Olfactory Lobe

Optic Tectum

Cerebrum Cerebellum

Medulla

Brain Structure

Shark

Olfactory Lobe

Optic Tectum

Cerebrum Cerebellum

Medulla