This site is 100% ad supported. Please add an exception to adblock for this site.

Mammalogy FW 317 OrStU

Terms

undefined, object
copy deck
List 16 physical trends and/or ecologically significant characters of mammals
1. Large size
2. Large proportion of community metabolism
3. generalists
4. intelligent in comp. w/other vert.
5. complex social behaviors
6. high levels of parental investment
7. high lvl. sensory perception (esp. hearing and olfaction)
8. homeotherms w/ insulative layer
9. simplification of skeleton
10. lactation all have nipples ex. prototheria
11. neopallium
12. specialized dentition
13. muscular diaphragm for respiration
14. epiphysis
15. loss of cervical and lumbar ribs
16. paired occipital condyles
The orders of most mammals arose in the... era of the....period aproximately ... mya. However, the earliest know fossils of mammals date back to the ... era in the ... period approximately...mya.
Most mammals arose in the EOCENE era of the TERTIARY approxiamtely 54-65 mya. However, the earliest know fossils of mammals date back to the TRIASSIC era in the MESOZOIC period approximately 248 mya.
Mammals are thought to have arose from a lineage of reptiles known as....
Therapsids which arose by the Lower Permian,
Therapsids (the group that includes mammals and most of their Upper Permian and more recent relatives) had appeared (Laurin and Reisz, 1990, 1996)
Synapida
Synapsids include mammals and all extinct amniotes more closely related to mammals than to reptiles.

Synapsids are the dominant large terrestrial animals worldwide, and they have also invaded the oceans (whales, pinnipeds) and the air (bats). The oldest known synapsid is an ophiacodontid from the Middle Pennsylvanian (320 million years ago)
Cynodonts
*Diverse group of Therapsids
*"Dog teeth"
*Dentary bone became majority of lower jaw
*zygomatic arch present --> from temporal shield
*Jaw muscle attachment moved from inner surface of temporal shield external surface of the brain case
*Heterodont teeth
Depauperate
Low number of species
A fauna, especially common on islands, lacking many species found in similar habitats elsewhere.

q
Sub class: Protheria
Order: Monotremata ("one hole" cloacea)
Family: Tachyglossidae
echidna
2 species in separate genus thus two monotypic genera
no nipples but pair of aeroli milk wicked by a tft of hair
Eats ant and termites
Myrmecophagous
Adaptations for Myrmecophagy
*no teeth
*very long tongue
*sticky saliva
*horny plate on roof of mouth-hard keratinized
*or muscular stomach
Ostelogical feature(s) of Order Monotremata that are similar to reptiles
Prefrontal bones and post frontals of the skull present (+in reptiles, - in mammals)

limbs articulated like lizards i.e. to the side
reproductive mode of
Tachyglossidae
Internal fertilization
lays single egg
incubation 7-10 days
both ovaries functional
(contrast with Orthirychidae rt. ovary lost)
Brains of Tachyglossidae have...cerebrum
have convoluted cerebrum
(thought to be a more dervived condition)

q
Sub class: Protheria
Order: Monotremata
Family: Orthirychidae
platypus
*no nipples or areolus glands in patch of lactic glands on ventral surface
*electro-senory organs in leathery beak
*venom gland associated with spike on hind legs (male only).
*teeth lost in embryological dev.
*nocturnal
*females lay two eggs w/protein coating that "glues" them together

q
Subclass: Theria
Infraclass: Metatheria
Order: Didelphimorphia
"new world opossums" (15 genera, 63 sp)
*50 teeth (more that eutherian ancestral number of teeth44)

q
Subclasss: Theria
Infraclass: Metatheria
Order: Dasyuromorphia
(3 famileis, 16 genera, 62 sp.)
e.g. tasmanian devil, numbat- (myrmecophagous)
Non-syndactylous

q
Subclass: Theria
Infraclass: Metatheria
Order: Diprotodontia
Koala other e.g. Kangaroo
(40 genera, 110 sp.)

q
Subclass: Theria
Infraclass: Metatheria
Order: Peramelemorphia
Bandicoots (7 genera 19 sp.)
*chrio-allantoic placenta (unlike other metatherians but similar to "higher" mammals)
some Characters of Monotremata
*No true teeth
*more reptilian skull (pre and post frontals)
*Cervical ribs (neck)
*limbs splayed to the side
*Oviparous with extraembryonic ectoderm in egg absorbs uterine secretions though porous shell
*retained cloacae
Chorioallantoic placenta
A placenta developed from the chorionic and allantoic extraembryonic membranes that replaces the choriovitelline placenta during the embryonic development of all eutherian mammals and some marsupials (peramelemorphia *bandicoots)
placenta
extraembryonic tissue that obtains nutrients from the endometrium of the uterus and secretes hormones to signal the state of pregnancy to the mother
Choriovitelline placenta
a placenta developed from the yolk sac that is characteristic of all therian mammals during early development
Chorion
the outer most extra-embyronic membrane of amniotes
amniotes
those vertebrates whose embryos posse an amion, chorion, and allantois in addition to the yolk sac of all vertebrates
coprophagy
refection
feeding upon feces (shrews, lagomorphs and rodents)
Chorionic villi
finger-like projections of capillaries from the outermost embryonic membrane that penetrate teh endometrium (of the mother); increase exchange between maternal and fetal systems
Metatheria brains
no corpus callosum
minimal development of neocortex
smooth
slow development
Metatheria reproduction
*internal fertilization
* females have bifurcated reproductive tract
*male have bifud penis and scrotum anterior to penis
*choriovitilline placenta (most)
*short gestation time (low nutrient exchange no or limited villi)
*endometrium folds after implantation
*accelerated development of anterior end of fetus (to climb from vagina to nipple)
* nipple/teat swells keeps dev. neonate in place for prolonged lactation period
*obligate lactation phase may be 2/3rds of total lactation period.
altricial
being hatched or born or having young that are hatched or born in a very immature and helpless condition so as to require care for some time
e.g. marsupial neonates except anterior end which is well developed
fossorial
adapted to digging <a fossorial foot>

Etymology: Medieval Latin fossorius used for digging, from Latin fossor digger, from fodere
:
semelparous
semelparity
reproduction that occurs only once during the life time of an individual
folivorous
folivory
consuming a diet of leave and stems
frugivorous
consuming a diet of fruit
e.g of semelparous mammal
Subclass: Theria
Infraclass: Metatheria
Order: Dasyuromorphia
Family:Dasyuridae
Genus Antechinus
jumping and ricocheting. jumping involves the use of all four feet; ricocheting involves the propulsion provided only by the two hind limbs
Saltatorial locomotion
Pelamorphia
Bandicoots
*chorioallantoic placenta (but no choriovilli)
Insectivora
hedgehogs moles shrews tenrics solenodons
*poor vision
*olfaction very acute
*"primative" smooth brains
*testes abdomial or scrotal, but anterior to penis
*some venomous species (often saliva)e.g. solenodons

q
Order: Insectivora
Family: Soricidae
*most numerous (# species) insectivora
*dicuspid incisors
*procumbant incisors in lower jaw
*no zygomatic arch
*rejected by mammalian predators
*All N. Amer. species have red tipped teeth
*smallest shrew micro sorex ~ 2.3 g

q
Order:Insectivora
Family: Talpidae
*complete zygomatic arch
*pelvis runs parallel to back bone
*birth canal does not go through pelvis

q
Macroscelidea: Insectivora
elephant shrews
*Dist. Africa
*robust zygomatic arch
*robust auditory bula
*large ears
*vision and olfaction important-different from insectivores
*pair territories marked with scent
*hindlimbs quadra-or-pentadactyl
*forelimbs are functional tridactyl
*diurnal (not typical small mammalian condition)
*molecular techinques indicate common ancestry with- Aardvark-elephants-hyraxes-mannatees
Paenungulate clade
Elephants (Order:Proboscidea)
Aardvark (Order: Tubulidentata)
Hyraxs (Order: Hyracoidea)
Tree shrews (Order: Macroscelidia)
Dugongs(Order: Sirenia)

q
Order: Scandentia
Tree shrews
*brians convoluted
*comlete auditory bulla
*Complete zygomatic arch
*well developed post orbital process
*long tail for counter-balance
*pentadactyl
*diurnal
*vocal
*may represent earliest lineages of primates

q
Order: Dermoptera
Colugos 1 fam. 2 genera 2 species
*glissant
*extensive flight membrane
*pectinate lower incisors
*foliovors
*nocturnal
*1 young at a time w/2 mo. gestation
*chambered intestine w/mircoflora
Describes a comb-like tooth. Consists of a series of projections like the teeth of a comb.
pectinate

e.g. Order: Dermoptera (tree shrews)
Describes teeth that project forward,
Procumbent

e.g. (Order: Insectivora Family: Soricidae)shrews
or kangaroos
(Order: Diprotodontia)
A web of skin, in this case the parachute-like extensions or flight membrane
Patagium
e.g. colugo (Order: Dermoptera) that is used for gliding
Bats (Order: Chiroptera)
Uropatagium(behind rear limbs)
Propatagium (Forearm)
Dactylopatagium (Between fingers)
Plagiopatagium (between fingers and body)

q
Order: Insectivora
Family : Tenrecidae
Tenrecs and otter shrews

q
Order: insectivora
Family: Erinaceidae
Hedgehogs
*only insectivors to under go treu hibernation
*spines
*"Old world" family
feed on fish
Piscivorous
some Chriopterans
Chiroptera
Two suborders: Megachiroptera, Microchiroptera
*known from early Eocene ~55 mya
*only right ovary funtional
*Hip joints and knee joints reversed
*only mammal w/ture flight
*digits elongated (except pollex)
*show greater degree of specialization than any other mammalian order
*Sperm is stored in interine tract, and ovulation and subsequent fertilization occur in spring
consuming pollen and nectar from flowers
Nectivorious
consuming blood
Sanguinivorious
Four factor of flight in Chiroptera
1)exterme weight reduction of the wing
2)maximized surface area (in relation to body) thus Low wing loading
3)High chamber (i.e. cross sectional curvature of teh wing)
4) leading edge flaps (propatagium) increased chamber
*3 and 4 produce lift
Microchiropterans
have several T-stat settings =?

And a reduced metabolism and ____rate
Microchiropterans are HETEROTHERMIC
and at rest they can reduce HEARTrate by an order or magnitude e.g. from 60 bpm to 600 bpm.
*excellent way to conserve energy
What adaptations might early insectivores have had that allowed proto-bats to occupy the night sky with the later adaptation to flight?
extant small mammals emit ultra-sonic sound and CAN hear them.
Thus the ability to echolocate was most likely in place before flight. thus a so called "preadaptation"
How do Megachiropterans the "key stone species" moniker?
Many plants in the Indo-Pacific rely on Megachiropterans for seed dispersal and seed conditioning for germination.
In addition some species are nectivores and pollinate flowers
What is the problem sanguinivorous bats face after feeding?
Sanguinivorous bats are "vampire bats" i.e. they drink blood.
*blood is mostly water thus in order to get enough food they must drink large quantities relative to there size. This would make they too heavy to fly.
*Their kidneys "work extra hard: to remove the water. as a consequence the bats urinate as they feed and reduce weight.
* once in flight their kidney slows the pace, to conserve water (blood = high protein, protein metabolism requires water.)

q
Class: Mammalian
Sub class: Theria
Infraclass: Eutheria
Order: Primates
Suborders: Strepsirhini lemurs
Haplorhini monkeys, apes
Characteristics of Order Primates
1.opposable Hallux Most(not homo sapiens)
2. opposable pollex
3.Most completely arboreal- brachiation
4. have nails instead of claws
5. most omnivorous
6. reduced rostrum
7. strongly binocular vision
8 large cerebral hemispheres

q
Class: Mammalia
Subclass: Theria
Infraclass: Eutheria
Order: Philidota Pangolins
1 fam., 1 genus, 8 species
Characters of Pholidota
Order: Pholodota
*"scales" Glutinated hair
*myrmecophagous
*toothless
*long tongue orgininates in STERNUM on modified cartilaginous ribs
*Pyloric portion of stomach modified to act as a gizzard
* Anal scent glands issue fetid oil
* Very Acute olfaction- species specific food selection by olfaction

q
Class:Mammalia
Subclass: Theria
Infraclass: Eutheria
Order: Tublidentata Aardvark
**Only Monotypic Order in Mammalia
Characteristics of Order Tubulidentata
Tublidentata
*only monotypic order
*few cheekteeth
*no incisors or canines (lost in fetal dev.)
*no enamel on oculsal surface
*Pulp tubule (in teeth) Name sake
*Very acute olfaction
* Convoluted complex turbinate in rostrum--> surface area for olfactory epithelium
*fossorial
*myrmecophagous
*digitigrade (but not fleet on feet)

q
Class: Mammalia
Subclass: Theria
Infraclass: Eutheria
Order: Lagamorpha
Families: Leporidae- Rabbits and Hares
Ochotonidae- Pikas
WW 2 fam., 13 genera, 80 species
OR 2 fam., 4 genera, 8 species
Characteristics of Lagamorpha
*large proportion of mammalian biomass
*thus ecologically dominant
*Dental formula 2/1, 0/0 long diastema
*2nd incisor (peg) behind front incisor
*incisors have enamel on both anterior and posterior surfaces
*fenestrated maxilla (esp. leporidae)
*Cheekteeth are hypsodont (high crowned)
*copraphagous
*herbivores
Difference between Rabbits and Hares respecting reproduction
Hares are Born PRECOCIAL
Rabbits are Born ALTRICIAL
Interspecific interactions
*Pikas (ochotonidae)are highly territorial
*Arctic Hares are social (herding behavior)
*European rabbits have warrens
****HOWEVER***** most are solitary
A gap between adjacent teeth, e.g. between incisors and cheekteeth in rodents and lagamorhs, artiodactyls, and perissodactyls
DIASTEMA
Feeding upon feces (as in lagamorphs, rodents and shrews)
Coprophagous
Coprophagy
Neonates that are born in a relatively undeveloped condition (i.e. eyes closed and with minimal fur present)
Altricial
A special type of protein-rich mammalian milk secreted during the first few days before and after birth of young

Why is it important?
Colostrum

contains ANTIBODIES that confers the mother's immunity to various diseases to the young
Born in a relatively well-developed state (open eyes, with fur, able to move immediately)and requiring minimal parental care.
Precocial

q
Class: Mammalia
Subclass: Theria
Infraclass: Eutheria
Order: Rondentia
most diverse mammalian order
WW 28 fam.,418 genera,2016+ species
OR 9 fam., 27 genera, 60 species
Characteristics of Rodentia
Order: Rodentia
*most diverse mammalian order
*single fossil group Paramyidae
*dental formula always 1/1,0/0 diastema
*may or may not have cheekteeth
*plantigrade
*Masseter muscle enlarged (aids in horizontal movement of the jaw
*Masster inserts anteriorly on rostrum
*(most ancestral form has middle masseter terminates on zygomatic arch)
*most are herbivores or granivorous
*some are omnivores e.g. Norway Rat
*some are insectivorious
*size range most 20-100 g but Capybara 50 kg
*ecologically diverse
Rodent reproduction
Order Rodentia
*induced ovulators (most)
*most have multiple births (Exception hibernators)
* males have an os baculum or penis bone
*may have gestation period prolonged by lactation (important in multibreeders)
*Bruce effect
Bruce Effect
In mice, the effect of a strange male, or his odor, that causes a female to abort and become receptive
A reduced heart rate associated with diving or torpor
bradycardia
Low-crowned teeth that have rounded, blunt cusps used primarily for crushing
Bunodont
Raccons Procyonidae have these and others
Human evolution
features of the human condition
Speech
manual dexterity
binocular vision
brachiation
bipedal posture
complex social structure
hidden ovulation
Human evolution why?
*Manual dexterity allows for tool use
*Bipedal posture freed the hands to carry objects => favors memory and planning
*"idle hand are the playground for evolution"
*hidden ovulation => UNCERTAIN PATERNITY
*Complex social interactions =>
-speech
-weapons food survival
cohesiveness
sex as a device to ensure group unity
manipulation of male aggression for the good of the group
estrous cycle
A sequence of reproductive events inluding hormonal, physiological
and behavioral that typically occur at regular intervals in a femalw mammal; generally divided into four stages:
*Proestrus
*estrus
*metestrus
*diestrus
Hardened , thich area on the skin;e.g. rough patches or outgrowths found on some speices of whales and ceropithecid primates
Ischial Callosities (on primates)
excrescences (on whales)
Of the two Suborders of Primates which tends to be nocturnal and which tends to be diurnal
Strepsirhini nocturnal Lemurs
Haplorhini diurnal
Where are the mammae on an Aye-Aye?
they are low on the abdomen or
INGUINAL
Four families in Xenarthra
Order:Xenarthra WW 4 fam, 13 genera, 29 species
ALL HAVE XENARTHROUS ARTICULATION OF THE LUMBAR VERTEBRAE
**Dasypodidae-armadillos
**Myrmecophagidae-New world ant eaters
**Bradypodidae-3-toed sloths (9 cervical vertebrae)
**Megalongchidae- 2-toes sloths (6 cervical vertebrae)

q
Order: Xenarthra
Family: Bradypodidae
3 toed sloths
9 cervical vertebrae
focal tree small range
returns to the ground to defecate at the base of the focal tree

q
Order: Xenarthra
Family: Megalongchidae
two toed sloths
6 cervical vertebrae

q
Order:Xenarthra
Family: Dasypodidae
Armadillos
*protected by fused bony scutes
*omnivorous-and/or insectivorous
*powerful digger
*SHED A SINGLE OVUM
- nine-banded one ovum 4 identical twins

q
Order: Xenarthra
Family: Myrmecophagidae
New-world ant eaters
*walk on knuckles of front feet( huge claws)
*plantigrade hind feet
*postal route feeder
*pyloric portion of the stomach functions as a gizzard
*toothless
*large salivary glands produce copious sticky saliva

q
Order: Cetacea
Suborder: Mysteceti (WW 3F,5G,10sp)
Families: Balaenidae
Balaenopteridae
Eschrichtiidae
Suborder: Odontoceti(WW 9F, 34G, 68sp)

q
Order: Cetacea
Suborder: Mysticeti
Family: Balaenopteridae rorquals
*pleated throat

q
Order:Cetacae
Suborder: Mysticeti
Family: Eschrichitidae
Gray whales

q
Order:Cetacea
Suborder: Mysticeti
Family: Balaenidae
Bowheads, N, S, Right Whales

q
Order: Cetacea
Suborder: Odontoceti
toothed whales
Characters of Order Cetacea
Cetacea
1.Obligate aquatic
2.fusiform body shape
3.front limbs are modified into flippers
4.hind limbs internal vestigial
(not connected to axial skeleton)
5. horizontal flukes
6. external nares migrated to dorsal surface of the head
7. premaxillary and maxillary have telescoped to form most of the roof of the skull
8. generally thick layer of blubber
9. Have rete mirabile in flukes and tongue (i.e. counter current heat exchangers)
Adaptations for diving
1.Two layers of capillaries in lungs for quick gas exchange
2. 2x erythrocytes (hematocrit= #RBC/vol blood)
3. 2-9 x myoglobin
4.bradycardia =slowed heart rate
5. shunt blood away from non-vital organs
6.physiological adaptations
*tolerant to lactic acid
* tolerant to CO2
Utilize up to 12% of O2 vs 4% for most mammals
Characters of the Order Carnivora
Carnivora
1. all have relatively large slightly re-curved canines
2. most have carnassial teeth (cutting shearing)
*Upper Premolar #4 lower Molar #1
3. all except Hyaenidae have Os baculum
4. Condyloid process usually articulates in a trench like GLENOID FOSSA
*lessens lateral movement of jaw
5. all have tapetum lucidum
6. most carnivora are omnivorous
*Felids and Mustelids are most carnivorous
7. In terrestrial carnovors olfaction is their primary sense
8. most have a Sibaceaous gland
a reflective layer, made of guanine crystals, lying outside the receptor layer of the retina that causes "eye shine"
Tapetum Lucidum
this structure aids in night vision by reflecting light that has passed through the receptor layer once and causes it to pass through the receptive layer a second time.
Carnivora suborders and families
Order:Carniovra
Suborder: Caniformia
Families: Canidae
Mustelidae
Mephitidae
Ursidae
Procyonidae
-----------
Phocidae
Odobenidae
Otariidae
Suborder: Feliformia
Families: Felidae
Hyaenidae
Viverridae
Herpestidae
In odontocete dolphins cavity filled with oil used to focus sound for echolocation
Melon
The auditory bullae and the middle ear apparatus of whales; not fused to the skull so that the direction of incoming sound waves can be determined.
tympanoperiotic
within the suborder Caniformia the families ursidae and mustelidae are thought to be most closely related to what two families of marine mammals respectively
Mustelidae --> Phocidae
Ursidae --> Otariidae
What fossil group are thought to be the "root stock" for all rodents
Paramyidae ~late Paleocene ~ 55 mya
What three orders are included in the unofficial group "Subungulates"
Proboscidea
Hyracoidea
Sirenia
Characters of the order Proboscidea
Elephants 1 family 2 genus 2 species
Mammoths lived until ~ 4700 years ago on Wrangle Island
1. 1 primary functional tooth
2. definite horizontal tooth replacement
3.tooth molariform
4. long gestation 20months 1-2 years of lactation
5 megaherbivore--> influences rates and patterns of recruitment (plants)
6. Tusks upper incisor
7. Skulls have pneumatic cavities
Characters of order Hyracoidea
Hyraxes
1. dental formula 1/2,0/0 diastema
2.plantigrade- 4 dig.frt. 3 Dig. bk.
3. maybe heterothermic
sleep in piles and bask
4. most are herbivores
5.dorsal skin gland -group cohesion?
6.Precocial young
7.8 Month gestation
8. 1-6 young
definite horizontal tooth replacement:
definite: there are a finite number of teeth in a life time
horizontal: teeth move forward or to replace teeth that are worn-out
Manatees and Dugongs
Order and families
Both are in the Order Sirenia
Trichechidae --> manatees
Dugongidae --> Dugongs
Contrast the two families of Sirenia
Trichechidae: 6 cervical vertebrae
*spoon shaped tail
*premaxillary small
*nasal bone present
*teeth with indefinite horizontal tooth replacement
Dugongidae:
*notched tail
*premaxillary large
*nasal bones absent
*very few teeth
The skeletal bones of Trichechidae and Dugongidae are large and dense, what is the term for this
pachyostotic
Common features of "ungulates"
(Orders Perissodactyla, and Artiodactyla)
*Hooves= Nails
*ungulagrade
*nuchal ligament-->calaginous tissue
*springing ligament--> elastin fibers
*almost all are herbivore
*all have large fermentation chamber
Perissodactyla
WW: 3 fam. 6 genera, 16 sp (most endg.)
*Origin NA
*greatest diversity in Eocene (~50 mya)
*decline ~25 mya coincident with rise of Artiodactyla
*monogastric w/caecum
*Mesaxonic
*variable tooth number
(rhinos 24-34, horses 36-42, Tapirs 44)
SPINE NOT FLEXIBLE
A complex mass of intertwined capillaries specialized for exchange of heat or dissolved substances between counter current flowing blood
rete mirablie
A group withn the generalized ancestral Order Condylarthra from which what orders are thought to have evolved from?
Also called the Subungulates
Probosidea
Hyracoidea
Serinia
Having a weight-bearing axis of a limb pass through the third digit_________
as in the order____________
Mesaxonic
Perissodactyla
Having a weight-bearing axis of a limb pass through the third and fourth digits is called_____________ as in the order ____________.
paraxonic
Artiodactyla
Order of "ungulates" with paraxonic limbs
Artiodactyla
WW 10 families 80 genera 220 sp.
native to all land areas except Australia
ruminants
Flexible SPINE

q
Order: Proboscidea

q
Order: Hyracoidea

q
Order: Sirenia
Family: Dugongidae

q
Order: Sirenia
Family: Trichechidae

q
Order: Perissodactyla

q
Order: Artiodactyla

q
Order: Carnivora
Suborder: Caniformia
Family: Mephitidae

q
Order: Carnivora
Suborder: Caniformia
Family: Canidae

q
Order: Carnivora
Suborder: Caniformia
family Otariidae

q
Order: Carnivora
Suborder: Caniformia
Family : Odobenidae

q
Order: Carnivora
Subfamily : Feliformia
Family: Felidae

q
Order: Carnivoria

q
Order: Carnivoria
Suborder: Caniformia
Family: Procyonidae

q
Order: Carnivora
Suborder:Caniformia
Family: Phocidae

q
Order: Carnivora
Suborder: Caniformia
Family : Ursidae

q
Order; Carniovria
Suborder: Caniformia
Family: Mustelidae

q
Order: Carnivoria
Suborder: Feliformia
Family Viverridae

q
Order: Carnivora
Suborder: Feliformia
Family Herpestidae

q
Order: Carnivora
Suborder: Feliformia
Family: Hyaenidae
Characters of Order Montremata
epipubic bone in both sexes
sperm are filiform
Cloaca
no teeth
mammary glands
no teats
four parts of a ruminant stomach
1. Reticulum
2. Omasum
3. Rumen
4. Abomasum
"True" stomach in ruminats
has acid and kills symbiotic microorganisms
Abomasum
Teeth with low crowns
brachyodont
cheekteeth charaterized by transverse ridges on their grinding surfaces
lophodont
six families included in the sub order Ruminantia
Traqulidae
Moschidae
Giraffidae
Antilocapridae
Bovidae
Cervidae
three of the four chambers of a ruminant stomach are derived from the _________.
the rumen reticulum and the omasum are derived from the esophagous
The microbes in ruminants break down cellulose to produce
VFA volatile fatty acids such as
Acetic acid Butric Acid and Proprionic Acid (-> succinyl-CoA-> ->->glucose)
Ruminant saliva
use urea to produce saliva
thus liquidy and alkaline
*microbes use urea as non-protein nitrogen to build their own proteins
Hindgut fermentation occurs in the
Cecum
Part of ruminant stomach that where the "cud" is formed
reticulum
reasons why foregut fermentation tends to be more efficient thatn hindgut fermentation
1.microbes work before the small intestine
2. mirobes digested for food source in Abomasum (by acids)
3.rumen can detoxify alkaloids in plants
general name for lemmings and voles
arvicolines
Stages in estorus cycle
Anestrous -> Proestrous -> 1.Estrous -> Fertilization-> gestation-> parturition -> lactation -anestrous
OR
2a.Estrous-> no fert. Metestrous -> anestrous
(monoestrous)
2b. Estrous -> no fert. -> metestrous -> diestrous ->proestrous (polyestrous)
If a female mammal is not fertilized during estrous and moves from metestrous to anestrous this animal is said to be
monestrous
e.g. panda
If a female mammal is not fertilized during estrous and moves from metestrous to proestrous this animal is said to be
polyestrous
e.g deer
the development of sperm is called
spermatogenesis
Hormones involved in the estrous cycle
FSH (anterior pituitary)
LH (posterior pituitary)
Progestrone (ovaries)
estrogen (ovaries)
hormone levels in estrous cycle
Follicle stimulating hormone
*produced in low levels by the anterior pituitary
*stimulates follicular growth
*growing follicle releases estrogen
*low levels of estrogen retard FSH and LH
*sharpe rise in estrogen as follicle matures causes sharp increase in FSH and LH
*ovulation occurs FSH and LH levels drop
*Corpus luteum grows produces high levels of progestrone and estrogen
*progestrone
-inhibit FSH (stops maturation of other follicles)
-stimulates LH -> thickening of endometrium
releases progestrone and estrogen after a follicle ruptures
corpus luteum
hormone:
*stimulates production of LH
*prepares uterus for implantation
*inhibits FSH production during pregnancy
*produced in the corpus luteum
progesterone

q
Subclass: Theria
Infraclass: Metatheria
Order: Diprotodontia
*shortened dentary bone
*elongated lower incisors
Koala other e.g. Kangaroo
(40 genera, 110 sp.)
A hormone produced by the posterior pituitary that causes contractions of the uterus during parturition, enhances milk "letdown", and is important for imprinting
e.g. parrie voles(mates) and ofspring/mother
oxytocin
A hormone produced by the anterior pituitary gland that has actions relating to reproduction and water balance. e.g. milk production, and corpus luteum function
prolactin
A condition found in some neotropical bats ans characterizeed by a reduced growth rate of the embryo following implantation.
Delayed development
e.g.micro- and megachiropteria,
possible response to unpredicatble insect species(prey)
The postponement of embeding of the blastocyst in the uterine epithelium for several days or months
delayed implantation
some insectivora, rodents,(facultative) bears, mustelids, seals, armadillos (obligate), some bats, 2 sp. roe deer.
A period of arrested development of an embryo at the stage of bastocyst(70-100 cells)
Embryonic diapause
changes in lactation i.e. prolonged bouts of lactation
kangaroos, and wallabies (Diprotodontia)
detriments to groups living
*increased exposure to disease/parasites
*Competition for:Resources=
(Food mates space)
Potential benifits of group living
protection from predators:
a)group defense
b)selfish herd phenomenon (minimize prob. of mortality)
c)multiply eyes, ears and noses
More efficient capture/explotation of food
(e.g.more time to eat per animal/per watchout)

THUS energeticly efficient
"corner stone of mammalian sociality"
LActation
mother/infant connection =all mammals
physical/chemical connection

THUS mammals have matrilineal sociality
Communication types
olfaction: musk glands
absentee com. urine feces scratching, foot fall
expression: eyes ears mouth
a retraction of the upper lip exhibited soon after sniffing the anogenital region of another or while investigating freshly voided urine
flehmen
living and breeding near the place of birth
philopatric
a mating system in which both males and females mate with several members of the opposite sex
polygamy
a mating system in which some males obtain more than one mate and females provide most of the care of ofspring
polygyny
selection favoring rapid rates of reproduction and growth; especially amoung species that specialize in colonizing short-lived unstabel habitats
r-selection
the gradual deterioration of function in an organism with age,leading to increased probability of death
senecence
Features of Eutherian reproduction
*Internal fertilization
*embryo implantation
*prolonged development
*chroionic villi
*chorio-allantoic placenta
*gestation much longer
*precocial young
*vestigial yolk sac
*active transport of nutrients and metabolic wastes
Features of Metatheiran reproduction
*Internal fertilization
*embryo nourished by uterine glands (not milk)
*small yolk sac
*membranes of the Ovum homologous with reptilian ovum
* chrio-vitelline placenta
*embryo NOT nourished by maternal blood supply
Features of Prototherian reproduction
*Internal fertilization
*large egg~ 3mm -> passes to oviduct
*no gestation -> egg laid
*embryo lives on stored yolk
*glandular fields in oviduct secrete substances add albumin to egg
Mature follicle-last stage before ovulation
Graafiam follicle -> ruptures egg expelled
Darwin's four potulates
1)VARIATION: There are differences between indivduals within a population
2)Inheritance: There is a correspondence between the characteristics of parents and those of their offspring
3)Competition: Survival and reproduction is limmited by available resources (i.e. there are more offspring produced than can possiblly survive)
4)Natural Selection: Correspondence between individual characteristics and survival and reproduction
information potentially conveyed by absentee communication
*age
*sex
*date (strength of signal)
*intent (aggression or reproductive phermones)
Uses of absentee communication
*avoid conspecific conflict
*find mates
*find group
*resource management (e.g. cougars avoid conflict within overlapping ranges)
**Overall advantage minimize energy expense
Factors that make dispersal a high risk endevour for juvenils
*low experience
*low hierarchical status
-> chronic stress -> high mortality
Why do juveniles disperse give the high risk
*physically driven out by mothers and other females
*"forced" out by their own physiology
*will have low chance of breeding in maternal home range
population dynamics
what determines rate of reproduction
*age of 1st reproduction
*young per year
A form of adaptive hypothermia or dormancy in which body temperature, heart rate, and respiration are lowered
torpor
Behavioral adaptations for optimizing energy budgets
*migration
*hibernation
*prolonged inactivity
*basking
*daily activity patterns (i.e. nocturnal to avoid heat)
*fossorial
*wallowing
*water storage
adaptation in Oryx that allow body temp to rise up 113 degrees fahrenheit and yet keep theri brain cool
sinus cavernosum
Two type of population cycles
Short cycle:3-5 yrs.(vicolines=lemmings, voles)non-synchronous
long cycle: 9-10 (snowshoe hares/lynx, musk rats)synchonous across continents but not between continents
**Cause trophic dynamic=forage resource and predators
explains more cycling in northern latitudes slower bio/geo cycling
bones of the mammalian ear are homologus with
bones of the lower jaw in earlier vertebrates
articular=>malleus
quadrate=>incus
stapes=>stapes

Deck Info

187

permalink