Lecture 4a: Skull and Teeth Flashcards
1) What is the proper name for the lower jaw
2) describe what is it used for in marine mammals?
3) what bone does it articulate with?
4) what bone is it in contact with?
1) Manidible
2) to obtain food to enter the digestive tract
3) with the skull
4) maxilla (upper jaw)
What can the shape of the skull reflect? Contrast this between a cetacean with a short blunt skull vs. Long narrow skill)
Exhibit the maker of how they hunt or forage for their food becuase it acts as a organ for sound reception
Pelagic
- what two areas can you find pelagic fish and define each
- decried the 4 main pelagic zones and their more common names
Inhabit the water column (Not bottom or shore)
- coastal (up to depth 655 ft; above continental shelf)
- oceanic (below continental shelf)
Epipelagic = sunlight mesopelagic = twilight Bathypelagic = midnight Abyssophelagic = lower midnight
Demersal
On or near bottom
Benthic
In the bottom
Ie: sediment
Skull: frontal bone
Portion of the skull above the eyes and includes the forehead, roof other nasal cavity and roof of the orbits (bony socket) of the eyes
Skull: parietal bone
Protects the brain
Forms side and roof of the skull
Skull: temporal bone
Forms base and sides of skull
Skull: maxilla
Upper jaw bone
- support teeth and palate of skull.
Includes: eye sockets and lower parts and sides of the nasal cavity
Skull: orbit
Eye location
- made up of 7 bones which protects, supports, and maximize the function of the eye
Skull: Zygomatic Arch
Protects the eye
(Cheek)
- from temporal bone to maxilla
Masseter chewing muscles attaches here
Skull: Area of Turbinates
Warms and moistens air
Structure made up of mix cartilage/bone to warm and moisten air
Skull: Mandible (lower jaw)
Bone that forms the lower art of the skull (support teeth) and with maxilla the mouth
Skull:
Compare shapes and location for sea otter
have really small heads, large zygomatic arch, large area of turbinates, parietal bone is larger, small frontal bone, enlarged maxilla and mandible
They are carnivores that use their teeth in a more diverse fashion for tearing and cracking of food.
Skull:
Compare shapes and location for crab eater seal and bearded seal
Crabeater seals are carnivores that use their teeth to strain from the ocean water
Bearded sea are carnivores that use their teeth to capture small fish (flat teeth, gums are worn down; 34 teeth flat and thicker)
Skull:
Compare shapes and location for Dolphin
Dolphins are carnivores with teeth that are uniform and conical in shape and used to capture prey
- cannot identify different kinds of teeth