Integrated Principles of Zoology, 11e

1
Lepidosuauromorpha
Class Osteichthyes
Class Chondrichthyes
Class Mammalia
Dinosauria
Crocodilia
Testudines
Class Amphibia
Class Agnatha
Class Aves
Archosauromorpha
Diapsida
Eureptilia
Sauropsid opening
Amniota
Amniote egg present
Tetrapoda
Girdles and limbs
Teleostomi
Vertebrates with endochondral bone
Gnathostomata
The jaw-bearing vertebrates
Subphylum Vertebrata
Vertebrae and cephalization
2
Bone formation
Can occur two ways.
1) Endochondral Bone
Also called cartilage replacement bone.
During ossification (mineralization with
CaPO4) a cartilage model is replaced
2) Dermal Bone
Think of this as skin bone
Dermal bone
Forms in the dermis of the skin
No cartilage model or precursor
3
Extinct agnathans
Several groups were armored
with dermal bone.
Internal skeleton is cartilage.
Dermal bone is phylogentically older.
Teleostomi
Bony fish plus tetrapods
Internal skeleton is endochondral bone.
Sheets of dermal bone incorporated into skull
roof.
Dermal bone used as armor in many forms.
4
Lepidosuauromorpha
Class Osteichthyes
Class Chondrichthyes
Class Mammalia
Dinosauria
Crocodilia
Testudines
Class Amphibia
Class Agnatha
Class Aves
Archosauromorpha
Diapsida
Eureptilia
Sauropsid opening
Amniota
Amniote egg present
Tetrapoda
Girdles and limbs
Teleostomi
Vertebrates with endochondral bone
Gnathostomata
The jaw-bearing vertebrates
Subphylum Vertebrata
Vertebrae and cephalization
dermal bone
5
Characteristics of Tetrapoda
Girdles
and limbs
A very primitive amphibian
Pectoral girdle
Pelvic girdle
Fore limb
Hind limb
Limbs of all tetrapods have the same basic
components.
6
Lepidosuauromorpha
Class Osteichthyes
Class Chondrichthyes
Class Mammalia
Dinosauria
Crocodilia
Testudines
Class Amphibia
Class Agnatha
Class Aves
Archosauromorpha
Diapsida
Eureptilia
Sauropsid opening
Amniota
Amniote egg present
Tetrapoda
Girdles and limbs
Teleostomi
Vertebrates with endochondral bone
Gnathostomata
The jaw-bearing vertebrates
Subphylum Vertebrata
Vertebrae and cephalization
7
Always has three embryonic membranes
(1)
Amnion
(2)
(3)
8
Synapsids
Anapsids
Lepidosuauromorpha
Class Osteichthyes
Class Chondrichthyes
Class Mammalia
Dinosauria
Crocodilia
Testudines
Class Amphibia
Class Agnatha
Class Aves
Archosauromorpha
Diapsida
Eureptilia
Sauropsid opening
Amniota
Amniote egg present
Tetrapoda
Girdles and limbs
Teleostomi
Vertebrates with endochondral bone
Gnathostomata
The jaw-bearing vertebrates
Subphylum Vertebrata
Vertebrae and cephalization
9
po
sq
j
q
po postorbital
sq squamosal
j jugal
po
sq
j
q quadrate
q
(and mammals)
po
sq
j
q
10
Skeletal system
Major components
Skull,
vertebrae,
ribs
Axial skeleton -
Appendicular skeleton -
girdles
limbs
Function
Lever arms in locomotion,
Protection of internal structures
11
Skeletal system
Cranial skeleton
Postcranial skeleton
Major components
Skull,
vertebrae,
ribs
Axial skeleton -
girdles,
limbs,
Appendicular skeleton -
The vertebrate skull is produced by three major
components
The chondrocranium
Forms the braincase
Forms the jaws, gill arches, hyoid,
The splanchnocranium
Cartilages at the anterior end of the trachea,
glottis, epiglottis and larynx
The dermatocranium
Forms the skull roof, armor on top of skull
12
Cranial skeleton
Skeletal system
Major components
Skull,
vertebrae,
ribs
Axial skeleton -
The vertebrate skull is produced by three major
components
The chondrocranium
Cartilaginous in Agnathans and Chondrichthyes
This structure is replaced by endochondral bone
in all Teleostomi
13
The chondrocranium
is hidden by dermatocranium
14
The chondrocranium
Is still visible in the cat
As the skull bones on which the brain rests
Basisphenoid presphenoid alisphenoid
And the bones surrounding the foramen magnum
The occipitals
15
Skeletal system
Major components of the skull
1) The chondrocranium
the brain basket
2) The splanchnocranium
Forms the jaws, gill arches, hyoid,
16
chondrocranium
Splanchnocranium is in blue
Chondrocranium is in black
17
Branchial Arches
Jaws
Hyoid Arch
17 - palatoquadrate cartilage
9 - hyomandibular
6 - epibranchial
5 - ceratohyal
4 - cerabranchial
11 - Meckles cartilage
Serial homology is an important concept
18
Early Stage of Skate Embryo
19
The splanchnocranium
Is represented in the cat skull
by dermal bone
That grows around the embyrological palatoqudrate
and mandibular cartilages
Maxilla
premaxilla
palatine
pterygoid
Dentary
20
Skeletal system
Major components of the skull
1) The chondrocranium
Brain basket
2) The splanchnocranium
Jaws and gill arches
3) The dermatoocranium
Forms the skull roof, armor on top of skull
The shark has no dermatocranium
21
Dermal bones of the skull roof
are the most obvious elements
in dorsal view
nasal
frontal
parietal,
squamosal,
jugal,
22
(No Transcript)
23
Skull Anterior View
E.N. Marieb 6th ed. Figure 7.2a
Figure 7.2a
24
Lateral view of human skull
E.N. Marieb 6th ed. Figure 7.3a
E.N. Marieb 6th ed. Figure 7.3a
25
Occipital Bone and Its Major Markings
E.N. Marieb 6th ed. Figure 7.4a
Figure 7.4b
26
Inferior Veiw of the Human Skull
E.N. Marieb 6th ed. Figure 7.4a
Figure 7.4a
27
Mandible and Its Markings
E.N. Marieb 6th ed. Figure 7.8a
Figure 7.8a
28
Developmental Aspects Fetal Skull

• Skull bones such as the mandible and maxilla are
  unfused

E.N. Marieb 6th ed. Figure 7.33
Figure 7.33