#exam 2

[biol525-mammalogy]

here's a better look at the cervid vacuity fenestra, just thought this was really cool :)

[biol525-mammalogy]

laurasiatheria -> carnivora -> caniformia -> pinnipedia -> odobenidae

i don't know what to tell you. it's walrus

[biol525-mammalogy]

laurasiatheria -> carnivora -> caniformia -> pinnipedia -> eumetopius jubatus (steller's sea lion)

way bigger than CA sea lions and with paler pelage. triangular postorbital process, homodont cheekteeth. nasals shaped like M

[biol525-mammalogy]

laurasiatheria -> carnivora -> caniformia -> pinnipedia -> otariidae -> zalophus californicus

external ears, triangular post orbital process, nasal bones have a notch shape on top like this (M)

[biol525-mammalogy]

laurasiatheria -> carnivora -> caniformia -> pinnipedia -> phocidae -> mirounga angustirostris (elephant seal)

key character: short nasals with a large nasal opening to accomodate the schnoz. other phocidae characters found here

[biol525-mammalogy]

laurasiatheria -> carnivora -> caniformia -> pinnipedia -> phocidae -> phoca vitulina (harbor seal)

no ears, spots on coat, large auditory bullae, incisors ungrooved, no postorbital process, eye orbits face up, nasals meet in a point like this (^)

[biol525-mammalogy]

laurasiatheria -> carnivora -> caniformia -> mustelidae -> pekania pennanti (fisher)

so i am not really sure if this skull has any unique distinguishable characters - it's got a eustachian tube and the rostrum is longer than sea otter; also the sagittal crest kind of makes a right angle

[biol525-mammalogy]

laurasiatheria -> carnivora -> caniformia -> mustelidae -> river otter (lontra canadensis)

pretty big, different from sea otter in that it has a dark dorsum and lighter venter instead of the light face and dark body