8/22/2015
SYNAPOMORPHIES Of Extant Mammals
1. endothermy (also in Aves) aided by hair
(insulation)
2. live birth (except for monotremes)
3. skin glands (including mammary glands)
Mammalian Characters: 2 Skin Glands
1. Sweat glands
A. Hypotonic secretions
B. Evaporative cooling
2. Sebaceous glands
3. Scent/musk glands
4. Mammary glands
A. Dayak bat
Hair, cont.
1. Hair Coloration
A. Cryptic
a. Matching
b. Disruptive
B. Aposematic
2. Molting
A. Continuous
B. Seasonal
C. Developmental
Mammalian Characters: 1 Endothermy
1. Definition
A. body temperature controlled by
metabolic activity and regulation of
heat exchange with the environment.
2. Role of hypothalamus
3. Advantages
4. Disadvantages
Mammalian Characters: 3 Hair
FUNCTIONS
1. Insulation and Homeostasis
2. Concealment
3. Signaling
4. Protection
5. Sensing
Mammalian Characters: 4, 5
4. FAT
A. not unique to mammals,
B. Energy storage
C. Thermal insulation
5. Mammalian Circulation
A. Four chambered heart
B. Erythrocytes without nuclei
C. Heart rate
1
8/22/2015
Mammalian Characters: 6 Respiratory System
Mammalian Characters: 7
Secondary palate with epiglottis
1. Complex Lung Structure
2. Muscular Diaphragm
Mammalian Characters: 8-9
8. Reproductive system
A. Female
B. Male
9. Brain
A. Neopallium
B. Corpus callosum
Evolution of the mammalian ear
THREE ear ossicles
1. malleus, incus, stapes
Mammalian Characters: 10, Senses
1. Olfaction: acute
2. Hearing
A. High acuity
B. Sound used in Communication,
Orientation, Locating food, Avoiding
enemies
C. Infrasound to ultrasound
D. External pinna
E. Middle ear with three ossicles:
malleus, incus, stapes
Mammalian Characteristics, cont.
2. Transformation of accessory jaw bones
A. mandible of dentary only
B. dentary-squamosal jaw articulation
C. tympanic bone
2
8/22/2015
Mammalian Characters: 10 Senses, cont.
1. Vision
A. photoreceptors
B. tapetum lucidum
2. Vibrissae
Mammalian Characteristics, cont.
1. Digestive System
2. Muscular System
A. Skeletal muscles
B. Superficial muscles
3. Skeletal System
A. Determinate Growth
a. long bones with epiphyses
Additional Mammalian Characters
1. heterodont teeth that occlude
2. diphyodonty
3. lateral movement of jaw
4. two occipital condyles
3