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?
Modified Scales
Chondrichthyes
1 Placoid Scales
2 Teeth
3 Mouth
Acrodont
Some Osteichthyes
Pleurodont
Amphibians
Reptiles
Thecodont
Crocodilians
Mammals
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
I
C
P
M
Incisors
Canine
Premolar
Molar
Tooth Pattern
Ruminant
I
C
P
M
Incisors
Canine
Premolar
Molar
Tooth Pattern
Carnivore
I
C
P
M
Incisors
Canine
Premolar
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
Pelycosaur
Extinct mammal
ancestors
Modern Mammals
Single
Temporal
Opening
Skull Structure
Diapsid
1
2
Two Temporal Openings
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
Lungfish
Gill-Breathing Amphibians
Evolution of Blood
Circulation
Conus Arteriosus of Frog
RA
LA
V
Evolution of Blood
Circulation
Crocodilians
Birds
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.
2.
3.
4.
5.
6.
7.
8.
IC
IL
P
Esophagus
Stomach
Duodenum
Intestine
Small Intestine
Large Intestine
Colon
Rectum
Cecum
Ileum
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
Cerebellum
Cerebrum
Medulla
Optic Tectum
Olfactory Lobe
Brain Structure
Mammal
Cerebellum
Cerebrum
Optic Tectum
Medulla
Olfactory Lobe
Brain Structure
Amphibian
Cerebrum
Cerebellum
Medulla
Optic Tectum
Olfactory Lobe
Brain Structure
Shark
Cerebrum
Cerebellum
Medulla
Optic Tectum
Olfactory Lobe