[2] Lecture 11-appendicular Skeleton Flashcards
(154 cards)
What species no longer possesses clavicles
Holsteans and teleosts
Main pectoral elements in bony fishes [crossopterygians, lung fishes, and chondrosteans]
Cleithrum
Composed of both dermal and endochondral components
Pectoral (shoulder) girdle
Dermal components of the pectoral girdle function:
Support endochondral components and articulate them w/ axial skeleton
Provides surfaces for muscle attachment
Dermal components include:
Cleithrum
Clavicle
Interclavicle
What’re the components carry the limb articulation such as the glenoid cavity
Endochondral
which component of the pectoral girdle Serves as major base attachment for limb muscles
Endochondral components
What’re the 3 endochondral components of the pectoral girdle?
Procracoid
Coracoid
Scapula
Do Sharks have endochondral and dermal components of the pectoral girdle?
No only endochondral components
Main component of the shark pectoral girdle?
Coracoid bar
Characteristics of the shark coracoid bar:
Carries fin attachment
Typically “u” shaped
Scapular processes sit on top of lateral ends of coracoid
What species lost the clavicle ?
Holosteans and teleosts
Fishes w/ clavicles?
Nope
Are the dermal components and the dermal skull components attached in tetrapod?
No dermal components are seperate from the dermal skull components
Where is the cleithrum in modern tetrapods?
There is no cleithrum in any modern forms.
Do tetrapods have interclavicle?
Inclavicle appears in fossil amphibians
Clavicles and interclavicles are present in:
Lizards and sphenodon
Furculum
Clavicles + interclavicle
In birds
Brace wings against sternum
Coracoid
Monotremes have clavicles?
Yes, interclavicles and clavicles
Do all animals have clavicles ?
No clavicles are lost in many animals
What is to note of the lack of connection btw pectoral girdle and skull in fossil and modern amphibians
Amphibians allowed for more freedom of movement of head
Cleithrum and clavicle are long slender rods located along anterior margin of scapula in
primitive tetrapods
What is the fate of original coracoid bar in tetrapods?
Becomes paired
Forms a scapulocoracoid cartilage on each side with a glenoid fossa in the middle
- -scapula is above the fossa
- –coracoprecoracoid region is located below fossa