Lab 9. Mammalia Flashcards
1
Q
Unique characteristics
A
- hair
- mammary glands
- sweat, oil and scent glands
- 1 lower jaw bone (dentary)
- heterodont dentition
- 3 middle ear bones (ossicles)
- anucleate red blood cells
- diaphragm
- advanced cerebral cortex
2
Q
2 subclasses
A
Prototheria (oviparous)
Theria
3
Q
Prototheria infraclass
A
ornithodelphia (monotremes)
4
Q
2 subclass theria infraclasses
A
- Metatheria
2. Eutheria
5
Q
Infraclass metathereia
A
viviparous, primitive placenta, marsupial pouch (marsupials)
6
Q
Infraclass eutheria
A
viviparous, complex placenta (placentals)
7
Q
Integument
A
- keratinized epideremis to protect from dehydration
- dermis = thick with many blood vessels for temp regulation
- sebaceous glands (lubricate and waterproof skin and hair)
- sudoriferous (sweat) glands for temp regulation
8
Q
Hair
A
- found on all mammals
- arrector pili muscle associated with each hair
9
Q
2 types of hair
A
- guard hair
2. undercoat
10
Q
guard hair
A
long, coarse, weatherproofing when coated with thin layer of oil
11
Q
vibrissae/whiskers
A
modified guard hair for sensory role
12
Q
undercoat
A
short, fine hair for insulation
13
Q
Locomotion
A
- 7 neck vertebrae (elongated or compressed)
- trunk = thoracic (articulated for flexibility) and lumbar regions (interlocking processes, support at cost of flexibility)
- sacral vertebrae and other bones in pelvic girdle often fused (good for locomotion, sucky for birth, but joint between pelvis halves loosens a bit before birth)
- last vertebrae are caudal: tail! good for locomotion, thermoregulation, balance. sometimes just coccyx
- appendicular skeleton rotated under body so faster movement
14
Q
Food acquisition and digestion
A
- lower jaw is single bone (dentary/mandible)
- 2 sets of teeth during lifetime (milk/primary/deciduous and permanent)
- Heterodont
- some are homodont like dolphins
- some like anteaters have no teeth
15
Q
4 different types of teeth
A
- incisors
- canines
- premolars
- molars
