L2 - Cranial Morphology

Right/sides, lateral

Medial/center

Anterior/rostral, the front

Dorsal

Ventral

Posterior/caudal

Distal

Proximal

the two parts of cranial skeleton

Neurocranium and Branchiocranium

Neurocranium and what it contains

part of skull that surrounds the brain, Chondrocranium (from cartilage) and Dermatocranium (from scales/dermal)

Branchiocranium

include jaws and gills

Bones in Ethmoid region

front most: Ethmoid and Vomer

Ethmoid

Ethmoid: front/Antermost skull bone

Vomer

Ethmoid: dentigerous/can have teeth

Bones in Orbital region

eye region, Frontals, Circumorbitals, Sclerotic

Frontals

Orbital: Paired, Largest bone on skull

Circumorbitals

Orbital: large bones that surrounds eyes in primitive fish

Infraorbitals

Orbital: small ring that surrounds eyes in modern fish

lateral line canals

Frontal, infraorbital and nasal (on top of ethmoid) house it, sense water flow

Sclerotic

Orbital: bones/cartilages in fish/non fish, surround eyes and is in it

Bones in Otic region

ear region: otic, Epiotics and Intercalars attachment site for posttemporal bone (back of skull), rotate head for feeding

Bones in Basicranial region

back base of skull, Exoccipital, Basioccipital, Supraoccipital, Parasphenoid, dont need to recognize from photos

Exoccipital

Basicranial: Surrounds foramen magnum (opening for spinal cord)

Basioccipital

Basicranial: Connects to 1st vertebra

Supraoccipital

Basicranial: has crest, point of attachment for muscles when pull head back for rotation 

Parasphenoid

Basicranial: Bar-shaped, between eyes

Bones in Branchiocranium: Mandibular Arch

oral jaws: upper jaw (Premaxilla, Maxillae) lower jaw (Dentary, Angular-articular, Retroarticular)

Premaxilla (pmx)

upper jaw: L shaped for jaw protrusion/suctioning, has teeth

Maxillae (mx)

upper jaw: move independent from Premaxilla but influence each other for modern fish

palatoquadrate

what the upper jaw is called for shark/relative (cartilage)

Dentary (d)

lower jaw: has teeth

Angular-articular (ang-ar)

lower jaw: behind dentary, point of roation for lower jaw

Retroarticular (rar)

lower jaw:  back of jaw, for some fish fused to Angular-articular

Meckel’s cartilage

what the lower jaw is called for shark/relative (cartilage)

Bones in Branchiocranium: Suspensorium

links skull/behind lower jaw and hyoid, Hyomandibula and Quadrate

Hyomandibula (h)

Suspensorium: top of it attach to skull on either side, can move jaw laterally/let it expand

Quadrate (q)

Suspensorium: Fan-shaped, Connects to lower jaw

Bones in Branchiocranium: Palatine Arch

Palatines

Palatines (pal)

Palatine Arch: sometimes has teeth, connect to roof of mouth

Bones in Branchiocranium: Opercular Apparatus

For respiration and feeding, covers gills: Opercle, Subopercle, Preopercle, Interopercle

Opercle (op)

Opercular Apparatus: largest

Subopercle (sop)

Opercular Apparatus: Most posterior/back

Preopercle (pop)

Opercular Apparatus: Anterior/forward, lies on top of others

Interopercle (iop)

Opercular Apparatus: most ventral/bottom

Bones in Branchiocranium: Hyoid Complex

Hyoid Complex and Branchiostegal rays

Hyoid Complex

in the middle of jaw and operculum/boney gill cover, useful for feeding (hyoid depression)

Branchiostegal rays

riblike, ventilate gill chamber and let water flow 

Branchiochranium: Branchial Complex

for respiration and feeding, contain gill arch and raker, boney fish has it modified to make second set of jaw in throat