Lab 6 Notes

Question 1

what do dermatocranial bones cover

Answer 1

every aspect of the animal’s head, with openings for the sensory organs

Question 2

what bones protect the animal’s skull

Answer 2

gular and opercular bones

Question 3

did the earliest tetropods have gular and opercuar bones

Answer 3

no - they lost it

Question 4

compared to the more recent lineages of fish, telosts have much () skulls

Answer 4

lighter

Question 5

anapsid

Answer 5

no temporal fenestrae

Question 6

synapsid

Answer 6

one temporal fenestrae

Question 7

diapsid

Answer 7

two temporal fenestrae

Question 8

what does the chondocranium protect

Answer 8

the brain, eyes, nasal organs, and inner ears

Question 9

what are the chondocranium bones grouped as

Answer 9

the otic bones, occipitals, sphenoids, and ethmoids

Question 10

what does the splanchnocranium support

Answer 10

the gills

Question 11

what does the first pharyngeal arch form

Answer 11

meckels cartilage –> quadrate and articular

Question 12

what forms the hinge joint in the jaws of the necturus, turtle, and aligator

Answer 12

quadrate and articular

Question 13

instead of the collumella, mammals use a series of what 3 middle ear bones

Answer 13

malleus, incus, and stapes – derived from the articular, quadrate, and hyomandibula/collumella

• used for hearing amplification

Question 14

what is the deratocranium derived from

Answer 14

the bony plates/scales of fish –> covers the delicate facial structures in fish such as muscles, arteries, veins, nerves, and especially the gills