resource for humans

potential predators on humans

pets

transportation

recreational hunting

risks (disease, parasites, damage to living area)

common ancestor of reptiles and mammals

evolved from amphibian-like tetrapods

shelled egg = adaptation from reproduction on land

temporal openings in the skull

synapsids have one

anapsids have none

diapsids have two

synapsids

1. pelycosauria (primitive herbivores)

2. therapsids (advanced top carnivores, mammal-like reptiles)

anomodontia

theridontia>gave rise to mammals (primary carnivores)

Herbivores:gomphodonts and tritylodonts

Carnivores: cynognathids and tritheledonts

tricuspid dentition

double-rooted cheekteeth

jaw structure adapted to different types of food

hearing (bidirectional)

post cranial skeleton allows for rotation

modified pectoral and pelvic girdles

thoracic ribs (flexibility)

primary jaw (dentary and squamosal bone)

diphyodont dentition

small in size

uncommon

nocturnal

includes monotremes 

"non-placental"

endothermy (fur)

mammary glands

live birth (few exceptions)

small carnivorous mammals (named for molars)

three cusps in a row |^^^|

omnivores with complex teeth

(most complex teeth in the jurassic period. contrast to reptilian teeth/jaw)

primary herbivores

molariform teeth

appeared at the same time as flowering plants

jut out horizontally (like rodents)

self-sharpening

used for shearing

1st appeared in multituberculata

family dryolestidae

made up of omnivores and marsupials

1. enlarged temporal opening (attachment of jaw muscle)

2. heterodont dentition (variety of food)

3. limbs beneath body (faster, more efficient mobility)> fused bones

4. decreased number of ribs (increased flexibility)

1. extinction of dinosaurs (opened up new ecological niches)

2. break up of pangea (species occupied different areas and adapted to the environment

hair/fur (insulation)

4 chambered heart (better circulation)

erythrocytes (red blood cells) are anucleate (for enhanced O2 ability)

females have mammary glands

muscular diaphragm (separates abdominal and thoracic cavities)

premaxilla

maxilla

cranium mandible

burrowing

grooming

defending

trophic level

tooth type determines what type of consumer

hard part of the tooth, resistant to friction

overlays the dentine

made up of crystallized calcium carbonate. can not regenerated

wear down over time

can be used to determine age

"enamel" for the roots

grows in layers each year (can be used for aging, like rings of a tree)

multiple types of teeth

well defined incisors, canines, premolars, and molars

single root

designed to cut/gnaw

tusks in elephants and narwhals

posterior to incisors

only 1 pair of upper, 1 pair of lower

single root

unicuspid

designed for tearing

the teeth in the back of the mouth

premolars and molars

posterior to canines

smaller than molars

2 roots

milk teeth (last teeth to be replaced)

most posterior teeth

3 roots

not replaced

used for grinding

gap in the mouth of rodents and logomorphs

missing canines (some premolars)

no use for tearing teeth

2 sets of teeth in lifetime

deciduous (milk teeth) replaced by permanent teeth

all teeth (except molars) have deciduous counterparts

(except elephants and manatees, replace teeth horizontally)

short hand description of total/number/position of teeth in a given species

front to back (upper/lower)

half of mouth

upper teeth: uppercase letter, superscript

lower teeth: lowercase letter, subscript

skin

the interface between the mammal and its outside environment

1st line of defense

separate internal tissues from outside conditions

water conservation (prevents evaporative water loss)

insulation (conserves body heat)

epidermis

dermis

hypodermis

1. inner stratum basale (bottom migrates up)

2. intermediate stratum granulosum (die at the top)

3. outer stratum corneum (dead layer. serves as protection)

cells that contain melanin

@ the boundary between the epidermis and dermis

pigment

acts as natural sunscreen

contains connective tissue

regulates heat loss

contains dermal arterioles and arrector pili

muscle @ the base of hair roots. Controls the hair follice.

Hair standing up:

conserved body heat

visual signal (behavioral)

layer where skin adheres to muscle

energy reserve (heat storage)

1. medulla (inner most)

2. cortex (majority of hair)

3. cuticle (outermost. clear and scale-like. allows hairs to interlock)

angora - long shafts which grow out. may or may not be shed

definitive - reaches only a fixed length, then shed

vibrissae

pelage

whiskers

tactile receptors/ sense vibrations

helps balance some species

long coarse guard hairs and underhair

awn - guard hairs with weak base

spines - enlarged guard hairs used for protection

bristles - firm, long hairs that form manes (angora)

wool - soft and curly

velli - "fuzz" the short fine hairs of newborns

pheomelanin - red and yellow hair

eumelanin - black and brown hair

(gray or white hair is due to the absence of melanin)

lighter color ventral shading, darker color dorsal shading

important in aquatic/arboreal animals

sebaceous glands

sweat glands

produce oil called sebum

greasy, toughens hair, keeps water off

eccrine: start functioning immediately after birth

apocrine: near hair follicles, begin functioning at puberty

sweat gland located deep within the dermis, connect via ducts

scent glands = modified sweat glands

mammary glands = functional in females. fatty milk nourishes young

used for climbing, fighting and digging

made up of unguis (top, curved portion) and subunguis (lower portion)

some claws can be retracted

cannot be retracted

subunguis is reduced. made mostly of unguis.

thickened unguis surrounds the subunguis

(subunguis = white line visible in horse hooves)

only present in bovids

core made of bone

encased in keratin

do not shed

occur in both sexes

present in rhinos

aglutinated cells, no core of bone

not shed. present in both sexes

made entirely of bone

velvet supplies blood

rutting: blood supply is cur off, velvet falls off (stop growing)

shed after mating season

grow back larger each year (more points)

neurocranium

dermatocranium

visceral skeleton

1. cervical (neck)

2. thoracic (back) 12-15 articulate with ribs

3. lumbar

4. sacral (often fused)

5. caudal (tail 3-50 depending on species)

protect vital organs of the chest cavity

vary in number in different species

clavicle and scapula

clavicle is reduced in felines

pubis

ichium

ilium

fused for form a ring

vestigial in cetaceans

for movement

voluntary control

striated and skeletal muscles

involuntary (operate on their own)

nonskeletal

smooth and cardiac

foot is planted

entire foot contacts the ground

foot is elevated

only the felanges contact the ground

good for running

1. support/stability

2. propulsion to move the body forward

3. manuverability

4. endurance

symmetrical

each foot is on the ground for half of one stride cycle

asymmetrical

each foot is on the ground for less than half of the stride cycle

e.g. gallop

posterior shift in body mass

enlargement of hip muscles

change in size and arrangement of pelvic bones to accomodate shift in mass

large hind feet (^surface area for easy landing)

long tail for balance

movement among the tree branches

plantigrade foot posture

prehensile limbs

opposable thumbs

opposable: able to touch each digit (old world monkeys)

partially opposable: able to touch some digits (new world monkeys)

eyes small, probably sightless

well developed tactile receptors in the snout

vibrissae may occur on tail, body wall, or legs

sense of hearing and smell are well developed

considered arboreal

evolved independently in several groups

patagium = extension of skin that stretches from body wall/neck to wrists and ankles

volant locomotion

only bats have mammalian flight

thick fur/blubber to conserve heat

webbing between toes increases surface area for propulsion

flattened tails for propulsion or as rudder

seals, sea lions, walrus

fully marine mammals that move onto land to give birth or avoid danger

dolphins or whales

fully marine, no time spent on land at all

regulation of constant body temp by physiological means

(a more precise term for endothermy)

emphasizes the variation in body temp under environmental conditions as opposed to the mechanism by which body temp is maintained

(use ectothermic behaviors)

metabolism of food or fat

cellular metabolism

muscular contraction

sunlight

reflected light

air temp

movement

air pressure

moisture loss

size/shape

orientation

thermostat

located in the forebrain below the cerebrum

operates by comparing change in body temp with a set point

different in each species

comfort zone

range of environmental temps for each species

(metabolic rate is minimal and does not change with ambient temp)

boundary "stuff stops working"

below = hypothermia

becomes necessary for animal to increase metabolic rate to balance heat loss

rate at which heat is lost from skin to the outside environment

slowed by insulation, shivering, curling up, etc.

lower body temp if animal cant maintain euthermy

loss of body function

temp above which the animal must dissipate heat to maintain a stable internal temperature

hyperthermia results

equalized

rate of oxygen consumption per gram of body mass

larger species live farther north, and smaller live farther south

(but actually the highest lattitudes animals are smaller. Less food and water available)

insulating value of fur is a function of length and density

long fur on my predators may interfere with hunting. Dense coats instead.

"felting" = gooming the hairs together to trap air layer. keep skin dry.

thick layer of blubber (fat) in whales/seals

form of dormancy characterized by lowering of body temp, met rate, respiration, and heart rate

during winter torpor is referred to as hibernation

during summer torpor is referred to as estivation

can last for hours or days

profound dormancy in which the animal remains at a body temp ranging from 2-5C for periods of weeks during the winter

largest mammal = marmot

bears don't hibernate, winter lethargy

increase thermogenic capacity:

muscular activity

involuntary muscle contractions (shivering)

nonshivering thermogenesis

adipose tissue

white - storage of lipid for insulation, endocrine organ for metabolisms

brown - all hibernating mammals. primary thermogenic tissue of most small hibernating mammal

intense heat during day

cold nights

limited water and cover

highly variable food supply

internal salt and water concentration

kidneys

concentrated urine and solid feces

osmoregulation

avoid euthermy

sweating and loss of salt

eating succulent veg

drinking available water

metabolically converting food to water

behavior - burrow

paired, bean shaped

dorsal part of abdominal cavity

outer portion = cortex

inner portion = medulla

renal pyramids in the inner medula, broad bases oriented toward cortex. 

renal papillae point toward pelvis

pelvis>ureter>bladder

diet

free drinking water scarce (succulent plants, body fluids of prey)

Metabolic water (cells oxidize food, cactus, seeds, halophytic plants for osmoregulation)

carnivores rely on food for water

evaporative coolign - reduces body temp. effective as long as unlimited water supply

insensible or transpirational water loss - occurs by diffusion through the skin and surfaces of the respiratory tract (sweating, panting, saliva spreading, and respiratory heat exchange)

apocrine - found on palms of hands and bottom of feet. not for thermoregulation

eccrine - distributed throughout body. secrete for evaporative heat loss

rapid, shallow breathing that increases evaporation of water from the upper respiratory tract

common for canids and ungulates

sweating has minimum control over degree of evap. contains large amounts of salt (osmoregulation)

panting - better controls degree of evap. do not lose electrolytes

fur minimizes rate of heat absorption

shiny, light colored pelage reflects sunlight and reduces heating 

1. the environment through conduction and convection plus radiation

2. metabolic heat gain

sum of the environ and metabolic heat gain

small mammals lose heat more readily than large mammals (SA:V ratio)

period of dormancy in reaction to hot or dry conditions

occurs in marsupials and insectivores but is most common among rodents

occurs at high body temp, lethargic rather than torpor