Homologies

Question 1

Skull: Chondrocranium

Answer 1

Sharks -
1) Chondrocraniuum

Actinopterygian -
1) NA

Reptile -

1) Exoccipital
2) Supraoccipital
3) Basioccipital
4) Prootic Opisthotic

Mammal -

1) Occipital
2) Temporal (Petrous portion (mastoid process + bones encasing ear)
3) Presphenoid and Orbitosphenoid

Question 2

Skull: Splanchnocranium

Answer 2

Shark -

1) Palatoquadrate Cartilage
2) Hyomandibular Cartilage

Actinopterygian -

1) Quadrate (homolog: palatoquadrate)
2) Hyomandibular (homolog: Hyomandibular Cartilage)

Reptile -

1) Quadrate (homolog: Palatoquadrate cartilage)
2) Epipterygoid (homolog: Palatoquadrate cartilage)
3) Stapes (homolog: Hyomandibular cartilage)

Mammal -

1) Incus (homolog: Palatoquadrate cartilage)
2) Alisphenoid (homolog: platoquadrate cartilage)
3) Stapes (homolog: hyomandibular cartilage)

Question 3

Skull: Dermatocranium

Answer 3

Shark -
1) NA

Actinopterygian -
1) NA

Reptile -
1) Squamosal

Mammal -
1) Temporal (Squamous portion: flat part, jaw joint, posterior zygomatic arch)

Question 4

Lower Jaw: Splanchnocranium

Answer 4

Shark -
1) Meckel’s Cartilage

Actinopterygian -

1) Meckel’s Cartilage
2) Articular

Reptile -

1) Meckel’s Cartilage
2) Articular

Mammal -

1) Meckel’s cartilage
2) Malleus

Question 5

Lower Jaw: Dermatocranium

Answer 5

Shark -
1) NA

Actinopterygian -
1) NA

Reptile -
1) Angular

Mammal -
1) Temporal (Tympanic portion: Tympanic of tympanic bulla