Lab 9 Flashcards
(49 cards)
Pelage
Entire covering of hair
Mammals are most easily identified by the presence of
Hair
Integumentary glands
Sweat glands
Sebaceous glands
Mammary glands
Sweat glands
Aid in thermoregulation by transporting water from skin to surface
Sebaceous glands
Produce oily substances released into hair follicles
Oils condition the hair and help maintain properties of the pelage like water resistance
Mammary glands
A defining characteristic of mammals, mammary glands are likely modified sweat glands
Pelage
Guard hair
Under hair
Vibrissae
Guard hair
The outer covering of the coat made up of longer, straight stiffer hairs with a smooth appearance
Protect the skin from water and sunlight and may be raised as a part of threat display
Under hair
Shorter and lacking in stiffness, under hairs are wavy and more numerous than guard hairs, under hair functions as insulation
Vibrissae
Whiskers
Serve as tactile sensory function
Cryptic coloration includes
Camouflage
Disruptive coloration
Countershading
Seasonal coloration
Mammalian head ornamentation
True horns
Pronghorns
Antlers
Ossicones
Rhinoceros horn
True horns
Unbranched and permanent, true horns are composed of a bony process with a keratinized covering or sheath
May be present on both sexes or only in males
Display seasonal growth rings
Pronghorns
Shed annually
Found in both males and females
Antlers
Antler vary in shape but all are highly branched and composed of bone with no keratinized sheath
Shed annually and covered with velvet (highly vascularized skin)
Typically only seen in males, except in caribous
Ossicones
Not true horns
Giraffe horns that are permanent, unbranched bony processes of the skull covered by skin
Rhinoceros horn
Composed of keratin with no bony core
Mammalians are grouped into
Prototheria
Theria (further branched into Metatheria and Eutheria)
Prototheria order
Order Monotremata
Order Monotremata
Platypus and Echidnas
Toothless and elongate jaw
Platypus with dorsoventrally flattened bill and tail
Echidnas with long tubular jaw and reduced tail
Platypus with shiny smooth pelage
Electroreceptors on leathery bills
Theria-Metatheria
Orders
Order Didelphimorphia
Order Diprotodontia
Order Didelphimorphia
Opossums
Plantigrade feet
Prehensile tail and opposable digit on their hind feet to aid in climbing
Marsupium
Fewer guard hairs
Tail long and scaled
Long snout
Prominent sagittal crest
Order Diprotodontia
Koala Wombats and Kangaroos
Two incisors of the lower jaw are procumbent (project forward)
Presence of diastema
Lack canine teeth
Relatively small braincase
Dorsal edge of the zygomatic arch (cheekbone) nearly as high as the top of the braincase
Order Afrosoricida
Tenrecs and Golden Moles
Convergent with true moles
Smooth shiny pelage
Reduced eyes and ears
Large broad claws
Short limbs
Short tail