Page 1
1
Chondrocranium
Dermatocranium
Splanchnocranium
Remodeling
Triple evolutionary sources
Chondorcranium Oken/Owen
Richard Owen
Chondrocranium
CHONDROCRANIUM
trabeculae parachordals occipitals sensory capsules
sphenoids ethmoids occipitals otic, optic, nasal
CENTERS OF OSSIFICATION
Page 2
2
CHONDROCRANIUM
General Functions1)Adult braincase
(chondrichthyes)
2) ScaffoldNeurocranium
SPLANCHNOCRANIUM(=Visceral Skeleton)
SPLANCHNOCRANIUM(=Visceral Skeleton)
1) support respiration
2) support feeding apparatus
3) later, jaws
SPLANCHNOCRANIUM
JAWS
General Functions1) Prey Traps
2) Crushing
Page 3
3
Derived from Gill Arches
Romer Jarvik
Jaw Suspension
Figure 7.56
Quadrate Incus
Articular Malleus
(Hyomandibula) (stapes)
Cuvier
Page 4
4
Quadrate Incus
Articular Malleus
(Hyomandibula) (stapes)
(Diarthrognathus) Probainognathus
Dermatocranium
DermatocraniumDerived from dermal Armor
Function
protect the brain
Page 5
5
FUNCTION1) Secondary
FUNCTION1) Secondary
2) Primary
respiration
feeding
prey traps
swallowing
Page 6
6
Water vs. Land FUNCTION(feeding)
Aquatic
SuspensionFeeders(cilia-mucus)
Agnathans
Suction Feeders(gape ‘n suck; inertial)
aquatic
Page 7
7
Bass Hog sucker
FUNCTION(feeding)
Air
Page 8
8
TongueSalamander
Salamander Salamander
LizardTongue
Page 9
9
Projectile Tongue
Gary Larsen
PrehensionJaws
FUNCTIONSwallowing
suspension
whole (gizzard)
mastication
Swallowing
Mastication
Page 10
10
SwallowingMastication
precise occlusionspecialized teethdiphyodont
(polyphyodont)
akinetic
CRANIAL KINESIS
Cranial kinesis
Kinetic
Akinetic
CRANIAL KINESISRapid change in size and configuration of buccalcavity.
Tooth position
Kinetic Kinetic
Page 11
11
Strike Kinematics
braincasesupratemproalquadrate
pterygoid ectopterygoidmaxilla
fang
mandible
prefrontal
MODEL (minus mandible)
Strike Kinematics