Exam 2 Flashcards
1
Q
what is an amniote
A
egg with extraembryonic membranes and a shell
2
Q
what are the 3 types of skull fenestration in amniotes
A
anapsid (no openings)
synapsid (1 opening)
diapsid (2 openings)
3
Q
which type of skull fenestration characterizes mammals
A
synapsid
4
Q
what are synapsids
A
pelycosaurs, mammals, therapsids, and cynodontia
5
Q
what are some synapsid traits
A
-maxilla contacts quadratojugal bone
-single fenestra
-caniniform maxillary teeth
-post dentary bones modified for hearing
6
Q
what are the 3 main groups of synapsids
A
pelycosaurs, therapsids, mammals
7
Q
what are pelycosaurs
A
eothyrididae, caseidae, varanopeidae, sphenacodontidae
8
Q
what are therapsids
A
biarmosuchia, dinocephalia, dicynodontia, gorgonopsia
9
Q
what are some defining features of therapsids
A
-enlarged temporal opening
-sagittal crest and zygomatic arches
-upper canines enlarged
-feet shortened
-more upright limb posture
10
Q
which group of therapsids are ancestral to mammals
A
cynodonts
11
Q
what are some defining features of cynodonts
A
-dentary bone becomes major lower jaw element
-partial secondary palate
-zygomatic arches flare laterally
-teeth absent from pterygoid bone
12
Q
what was the permian mass extinction
A
climate change due to large scale volcanism
13
Q
what are some reasons why cynodonts survived the permian mass extinction
A
-small body size
-fast life history (grow quick, reproduce early)
-burrowers
-mammalian (heterodont teeth, large brain, warm blooded, fur)
14
Q
what kinds of terrestrial vegetation characterized the mesozoic
A
ferns, cycads, ginkgophytes, bennettitaleans
conifers first appeared
early angiosperms appeared
15
Q
what are some skeletal and inferred soft tissue features of early mesozoic mammals
A
skeletal:
-double rooted cheek teeth w/ premolars and molars
-diphyodont dentition
-mandibular symphysis reduced
soft tissue:
-mammary glands
-viviparity
-anal and urogenital openings
16
Q
what are therian mammals
A
marsupials and eutherians
17
Q
what are the anatomical traits of therian mammals
A
-tribosphenic molars
-protocone of the upper molar occludes with the talonid basin of the lower molar
-supraspinous fossa on scapula
-spiral cochlea
18
Q
what is the evolution of a new dentary squamosal jaw joint
A
articular bone of lower jaw > malleus
quadrate bone of lower jaw > incus
angular bone of lower jaw > tympanic ring
19
Q
what is the evolution of more complex molars
A
primary cusp, accessory cusp, cutting trigonid, crushing talonid
20
Q
what is the evolution of the secondary palate
A
facilitated suckling
21
Q
what is the evolution of parasagittal movement of limbs
A
sprawling vs erect
22
Q
what is the evolutionary history of mesozoic mammalian radiations
A
-all continents except antarctica
-small bodied
-premolars/molars
-large brain
-lactation/suckling
23
Q
what are the basic characteristics of haramiyidans
A
-earliest known herbivores
-teeth resemble multituberculates
-molars are parallel rows of cusps
-jaw moved with powerful backstroke
24
Q
what are the basic characteristics of morganucodontids
A
-small, shrew like
-cheek teeth differentiated into premolars and molars
-premolars preceded by deciduous teeth
-chewing on one side of jaw at a time
25
what are the basic characteristics of docodonts
-highly derived roughly quadrate teeth, cusps not aligned anteroposteriorly
26
in what ways were haramiyidans, morganucodontids, and docodonts ecologically diverse
-docodonts swim and fish feed
-ambulatory carnivory or scavenging in large gobiconodontids
-scratch digging and feeding on colonial insects in fruitafossor
-climbing locomotion in basal eutherians and metatherians
-gliding adaptation in volaticotherium
27
australosphnidans are ancestral to which modern mammals
monotremes
28
what are the basic characteristics of eutriconodonts
unique molars
29
what are the basic characteristics of multituberculates
-herbivores or omnivores
-similar in appearance to rodents
-jaw movement similar to haramiyidans
30
define the clade boreosphenida
early mammals that originated in the northern hemisphere and has three cusped cheek teeth (metatherians and eutherians)
31
what is the significance of juramaia sinensis
earliest known marsupial
32
what is the significance of eomaia scansoria
earliest known placental mammal
33
what is the early rise hypothesis
ecological radiation of early mammals began prior to K-Pg boundary, driven by broadly coincident ecological radiations of flowering plants and some insect groups
34
what is the suppression hypothesis
mammals experienced ecological release following the end-Cretaceous mass extinction event at 66M
35
what is the delayed rise hypothesis
an ecological radiation occured in the eocene, possibly spurred by the paleocene-eocene thermal maximum at 56Ma
36
what is the basic climate of the epoch in the plaeocene
cretaceous subtropical
37
what is the importance of the site of corral bluffs, CO
K-Pg boundary
38
which paleocene mammals are considered ancestral to modern ungulates
condylarths
39
which paleocene mammals are considered ancestral to modern carnivores
miacids
40
which groups in the paleocene were the first to attain large body size
pantodonts and uintatheres
41
which modern groups of the paleocene are mesonychids and plesaidapiformes related to
artiodactyls
42
what is the basic climate of the epoch in the eocene
5-8 degree C global average temp rise, creatceous subtropical climate persisted
43
which group of ungulates has its peak of diversity in the eocene
perissodactyls
44
which modern group got its start in the eocene with the origin of the group archaeocetes
hippos
45
what are the 2 eocene groups of early primates
adapids (lemurs) and omomyids (tarsiers)
46
what is the basic climate of the oligocene
development of antarctic ice and changes in ocean circulation, brought about increased seasonality/overall cooling and drying
47
what was the grand coupure
eocene-oligocene climate driven extinction even
48
what is the significance of the paraceratherium
largest land mammal ever
49
which groups of primates originated during the eocene
aegyptopithecus and apidium
50
what is the basic climate of the epoch in the miocene
savannah woodlands dominate north america, semideserts, mountain building
51
which group of mammals had its peak of diversity in the miocene
proboscidean
52
which group of primates originated during the miocene
apes
53
what was the basic climate of the epoch in the pliocene
warming followed by continued global cooling, extensive glaciation
54
which south american group had its peak of diversity in the pliocene
ungulates
55
what was the great american biotic interchange
north america and south america attatched and northern mammals colonized a lot
56
which group of primates originated during the pliocene
hominids
57
what was the basic climate of the epoch during the pleistocene
periods of lowered temperatures alternated with periods of relative warmth, increased precipitation
58
what were the pleistocene megafauna
-saber tooth cats and imperial mammoths
-saber tooth cats and litoptern ungulates
-marsupial lions and short faced kangaroos
59
what is the evidence that supports the idea that humans caused the extinction of many pleistocene mammals
-archaeological evidence of co-occurrence and hunting
-non random extinctions
-immigrant species from asia less affected than native species
-dates of last known occurrence coincide with human migrations
60
what are basic mammalian trends
-endothermy/hair
-lactation
-sensory specializations
-heterodont dentition
61
what is the function of mammary glands in mammals
produce milk
62
what is the difference in milk delivery between monotremes and metatherians/eutherians
monotremes dont have external nipples
63
what is the function of sweat in mammals
promote evaporative cooling, eliminates some waste
64
what is the function of sebaceous in mammals
oily secretion that lubricates hair and skin
65
what is the function of scent and musk glands in mammals
attracts mates, marks territory, communication, protection
66
what is hair made of in mammals
keratin
67
what are the three layers of an individual hair in mammals
hair cuticle, cortex, medulla
68
countershading
upper body is darker than lower body
69
camouflage
hides an animal
70
disruptive coloration
strongly contrasting markings to break up the outline of an animal
71
warning coloration
warns predators
72
intraspecific communication
colors that mean something to another species
73
what is adipose tissue (fat) used for
-energy storage
-source of heat and water
-thermal insulation
74
where is fat often stored in mammals
tail or abdomen
75
what is the basic setup of the mammal circulatory system
systemic and pulmonary circuits
4 chambered heart
76
what is the basic setup of the mammal respiratory system
trachea > bronchi > bronchioles ? alveolar ducts > alveoli
77
what structures characterize the mammalian brain
-highly developed neocortex
-corpus callosum present
78
what characterizes the various mammalian sense organs
olfaction: receptors distributed across mucosal surfaces of mesethmoid and vomeronasal organ areas
hearing: high acuity, used in communication/orientation/food/enemies
sight: retina with photoreceptors
79
what 2 adaptations for fermentation are found in ungulates
foregut fermentation
hindgut fermentation
80
what are the characteristics of the mammalian skull
-akinetic
-zygomatic arch
-single crainomandibular jaw joint
-turbinal bones in nasal cavities
-foramina pass cranial nerves and vessels
81
what kinds of vertebrae are found in the mammalian axial skeleton
cervical
thoracic
lumbar
sacral
caudal
82
what are the 2 girdles for the limbs
pectoral and pelvic
83
what is the ancestral number of digits in the mammalian manus and pes
5
84
define crown
top of tooth
85
define root
portion of tooth underneath gum
86
define pulp cavity
inner tissue of tooth
87
define enamel
outer layer of tooth
88
define dentin
essential for support of the enamel layer
89
define cementum
outer layer of root
90
define rootless vs rooted teeth
rootless teeth continue growing (rodents)
91
what are the basic surface features of mammalian teeth
cusp - highest point of tooth
basin - lowest point of tooth
92
which bones produce teeth in mammals
dentary (lower jaw), premaxilla
93
define homodont
all teeth are the same shape
94
define heterodont
4 different tooth types
95
define diphyodont
two sets of teeth
96
define polyphyodont
several sets of teeth
97
what are some exceptions to the typical mammal pattern of teeth
-toothed whales
-manatees
-pinnipeds
-some rodents
-elephants
-kangaroos
98
define dental placode (what cells make up this)
where a tooth starts (interaction between epidermis and dermis)
99
define enamel knots
signals center to appear, marks the location sites of cusp formation
100
define ameloblasts
cells that produce enamel
101
define odontoblasts
produces dentin
102
define periodontal ligament
ligament that holds tooth in socket
103
what are the characteristics of tribosphenic upper and lower molars
upper - paracone and metacone on top, protoconule, metaconule, protocone on bottom
lower- protoconid and hypoconid on top, paraconid, hypoconulid, metaconid, entoconid on bottom
104
how do tribosphenic upper and lower molars occlude
the upper molar fits inside of the lower molar
105
what does the addition of hypocone have to do with tribosphenic upper and lower molars
cusp added to the primitively triangular upper molar teeth of therian mammals
106
cone vs conid
cone - upper cusp
conid - lower cusp
107
what is the function of the masseter muscle
close the jaw
108
what is the function of the temporalis muscle
close the jaw
109
what is the function of the medial pterygoid muscle
close the jaw
110
what is the function of the lateral pterygoid muscle
open the jaw and pull jaw forward
111
what is the function of the digastric muscle
raises tongue, opens jaw for chewing and speech
112
what are the diet related differences in mastication
how they chew determines what they can eat
113
dental formula?
goes from front to back, incisiors, canines, premolars, molars
114
what are the primitive placental and marsupial dental formulas
marsupial: 5/4, 1/1, 3/3, 4/4
placental: 3/3, 1/1, 4/4, 3/3
115
what are some edentulous mammals
-mysticete whales
-pangolins
-anteaters
-monotremes
116
what are some variations in mammal incisor teeth
rodents: large and chisel like
lemurs: tooth comb
aye-ayes: rootless
elephants: tusks
117
what are some variation in mammal canine teeth
modern carnivores: enlarged
118
define brachydont
short crowned teeth
119
define hypsodont
tall crowned teeth
120
define bunodont
rounded cusps on molars
121
define lophodont
cusps form ridges
122
define selenodont
cusps form crescents
123
define zalambdodont
v shaped crest
124
define dilambdodont
w shaped ectoloph
125
carnivory vs herbivory
carnivory: cheek teeth are blade like
vertical shearing
herbivory: cheek teeth become quadrate
jaw action became horizontal and transverse
126
what hormone is produced by male testes
testosterone
127
what are spermatogonia
sperm
128
what is spermatogenesis
mitosis of sperm
129
what are the differences in testes locations across mammals
abdominal:
-monotremes
-endentates
-elephants
-sirenians
-cetaceans
scrotum in:
most mammals
130
what is a baculum
bone
131
what are the greater number of functions required by females for reproduction
-make eggs
-receive and transport sperm
-gestate young
-birth/egg lay
-lactation
-parental care
132
what are the basics of oogenesis
ova mature in paired ovaries, takes place in fetus during gestation
133
what is the anatomy of the monotreme reproductive system
right and left uteri enter urogenital sinus, cloaca present
134
what is the anatomy of the marsupial reproductive system
pair of uteri enter into vaginal sinus, duplex cervix, two vaginas
135
what is the anatomy of the placental mammal reproductive system
retain paired ovaries, single vagina
136
what are the four different kinds of placental mammal uteri
duplex
bipartite
bicornuate
simplex
137
what are the ancestral characteristics of monotreme reproduction
-yolk with shell
-more yolk
-fetal egg tooth
-embryos at somite stage when laid
138
what is the sequence of events in fertilization and early embryonic development in monotremes
fertilized in infundibulum > mucoid coating added > thin shell of ovokeratin added > second shell membrane added > uterine secretions aid embryogenesis > third shell layer added prior to birth
139
what is the blastoderm
outer layer of egg
140
how do marsupials and placentals differ in length of gestation and lactation
eutherians have longer gestation, shorter lactation
141
define monoestrous
one estrous cycle per year
142
define polyestrous
more than one estrous cycle per year
143
4 phases of the estrous cycle
proestrus - development of endometrium and ovarian follicles
estrus - ovulation (luteinizing hormone LH)
metestrus - LH maintains corpus luteum, secretes hormones
diestrus - uterus is prepared for implantation
144
which hormone is responsible for ovulation
LH (luteinizing hormone)
145
what is the corpus luteum and what is its function
secretes hormones to prepare endometrium for implantation
146
what is spontaneous ovulation
occurs without copulation, occurs widely among mammals
147
compare and contrast the 3 types of marsupial estrous cycles
1: short gestation, no ovulation during lactation
2: gestation and estrous cycle length same, postpartum estrus and ovulation, embryonic diapause
3: same as 2 but w/ further development not controlled by lactation
148
what is the sequence of events in fertilization and early embryonic development in marsupials
spontaneous ovulation > fertilization > cleavage divisions > mucoid layer > shell membrane > shell membrane becomes placenta
149
what is the sequence of events in fertilization and early embryonic development in placental mammals
fertilization > cleavage divisions > blastocyst reaches uterus > outer layer adheres and erodes > forms placenta > forms embryo
150
what is the protoderm
a unique developmental layer in marsupials
151
what are the inner cell mass and trophoblast
inner cell mass forms embryo
trophoblast forms placenta
152
what is the chorioviteline placenta
highly vascularized portion of yolk sac
153
what is the chorioallantoic placenta
highly vascularized chorioallantoic membrane
154
describe the macropodidae placenta
choriovitelline
155
describe the peramelemorphia placenta
choriovitelline and chorioallantoic
156
describe the placental mammal placenta
chorioallantoic
157
define epitheliochorial placenta (which mammals have this?)
oxygen and nutrients pass through walls of uterine blood vessels and through layers of connective tissue and epithelium
-lemurs, some ungulates, cetaceans
158
define endotheliochorial placenta (which mammals have this?)
epithelium of the chorion is in contact with endothelial lining of uterine capillaries
-carnivorans
159
define the hemochorial placenta (which mammals have this?)
endothelial lining of the blood vessels in villi separate fetal blood from surrounding maternal blood sinuses
-insectivorans, rabbits, bats, higher primates, rodents
160
define the diffuse shape of eutherian placenta (which mammals have this?)
villi occur over large surface area
-lemurs, artiodactyla, perissodactyla
161
define the cotyledonary shape of eutherian placenta (which mammals have this?)
villi in regularly spaced clusters
-ruminant artiodactyla
162
define the zonary shape of eutherian placenta (which mammals have this?)
band of villi encircles chorion
-carnivorans
163
define the discoidal shape of eutherian placenta (which mammals have this?)
villi in disk shaped zone
-insectivorians, bats, primates, rodents, rabbits
164
what are the hormonal pathways involved in metatherian parturition
corpus luteum
165
which hormones trigger uterine contractions in metatherians
mesotocin
166
how does the fetus get into the pouch and what happens once it is in there
crawls into pouch, attaches to bud at tip of teat
167
what are the hormonal pathways involved in eutherian parturition
estrogen and lowering of progesterone
168
which hormones trigger uterine contractions in eutherians
estrogen
169
what is the difference between a deciduous or nondeciduous placenta
non: villi pull out of uterine pits
deciduous: placenta is torn away at birth
170
which hormones promote mammary gland development
estrogen, progesterone, insulin, placental lactogen
171
which hormone regulates lactation
prolactin
172
what are the three stages of metatherian lactation
mammogenesis: prep
early lactogenesis: young attach to teat
late lactogenesis: young are detatched
173
how do metatherians and eutherians differ in milk composition across the lactation period
eutherians: uniform
marsupials: varies
174
how do metatherians and eutherians differ in milk composition across species
marsupials: varies little
eutherians: varies lot
175
which requires more energy: pregnancy or lactation
lactation
176
what are the various costs of reproduction on female mammals
-increase food intake
-decrease activity
-metabolize fat
-shift diet
-anatomical changes
177
what is the foraging cycle strategy (and in which pinnipeds is this found?)
females forage at sea but return to nurse
-sea lions, fur seals
178
what is aquatic nursing strategy (and in which pinnipeds is this found?)
suckling at sea
-walrus
179
what is the fasting cycle strategy (and in which pinnipeds is this found?)
females rely on blubber and fast during lactation
-seals
180
what is the combination of fasting and foraging strategy (and in which pinnipeds is this found?)
fast sometimes, forage sometimes
-seals
181
what are the details of delayed fertilization and in which mammals does it occur
mate and store sperm in fall, fertilize in spring
-rhinolophid and vespertilionid bats
182
what are the details of delayed implantation and in which mammals is it found
development paused at blastocyst stage
-metatherians, carnivora, chiroptera, pilosa, artiodactyla
183
what is the difference between obligate and facultative delayed implantation
obligate: consistent part of reproductive cycle
facultative: occasions when animal is nursing large litter
184
what are the details of delayed development and in which mammals does it occur
blastocysts stops growing until newborn leaves pouch
-kangaroo
185
how does photoperiod affect the timing of reproduction
day > night
186
what is the effect of melatonin on reproduction
day > night
187
what is the effect of temperature on reproduction
warmer > colder
188
what is the effect of energy/nutrition on reproduction
plant secondary compounds and phyoestrogens
189
how do plant secondary compounds and phytoestrogens play a role in reproduction
PSC: chemicals that trigger reproductive behavior
phyto: plant compounds that mimic animal estrogens
190
how do behavioral controls influence reproduction
pheremones produced attract mates, signal receptivity
191
what is the bruce effect and in what mammals is this seen
unfamiliar male in habitat, females reenter estrus more quickly
192
why is it advantageous for a new male in a group to commit infanticide
male brings females into estrus more quickly
193
what are the characteristics of the altricial young strategy
-helpless at birth
-nearly naked
-ears/eyes closed
-cannot locomote or thermoregulate
194
how does the semelparity strategy affect males
death, males lose significant body weight and fur
195
what are the characteristics of the precocial young strategy
fur
eyes and ears functional
locomote and thermoregulate
196
what is the general rule relating gestation length and body size in mammals
positive correlation
197
what are some exceptions to the body size/gestation length rule in mammals
elephant shrews, sloths, baleen whales, primates
198
why is inbreeding avoidance important
mortality, susceptible to disease, genetic issues
199
what are some ways inbreeding is avoided
dispersal from natal area, kin recognition
200
how does environment influence the timing of reproduction
good season > more breeding
201
in what way does reproductive effort vary with residual reproductive value
varies inversely
202
define endothermy
internal heat production
203
define homeothermy
constant heat production
204
how are ectotherms different than endotherms
ecto- heat gained from environment
endo- heat produced
205
what are the advantages and disadvantages of being ectothermic
advantages:
-no high basal metabolic rate
-endure shortages of food/water/O2
-elongate shape or tiny
disadvantages:
-rapid exhaustion
-brief activity
206
what are the advantages and disadvantages of being endothermic
advantages:
-high work capacity
disadvantages:
-lots of food, water, O2
207
define regional heterothermy
core body temp is maintained well above that of other body regions
208
define temporal heterothermy
mammals modify their body temp in response to fluctuations daily seasonal environmental temp
209
how do core body temperatures vary within mammal groups
core body temp is constant but body temp varies
210
how do core body temperatures vary between metatherians and eutherians
metatherians - lower body temp
eutherians - higher body temp
211
what is the thermoneutral zone
zone in which little or no metabolic energy is expended on temp regulation
212
what does a mammal need to do if its body temp fluctuates below the lower critical temperature
additional heat production
213
what does a mammal need to do if its body temp fluctuates above the critical temperature
additional heat dissipation
214
how does food quality affect metabolic rates
better food quality = higher metabolic rates
215
4 strategies to dealing with cold
1) large body size
2) decrease rate of heat loss
3) increase metabolic heat production
4) abandon normal body temp
216
what does bergmann's rule describe
boreal mammals larger than tropical counterparts
217
what is the relationship between surface area and volume
surface area increases with square of linear dimension
volume increases with cube of linear dimension
218
what kinds of mammals have trouble staying cool
large
219
what kinds of mammals have trouble staying warm
small
220
what is the relationship between body size and a mammal's lower critical temperature
small: lower critical temp
large: higher critical temp
221
what is the difference between the basal metabolic rate and the field metabolic rate
basal- measured under controlled lab conditions
field - free living animals eating, digesting, moving
222
how does the mass specific metabolic rate vary with body size
smaller mammals have higher metabolisms
223
how does the absolute metabolic rate vary with body size
larger mammals have higher metabolisms
224
what kinds of insulation do mammals have
blubber
225
how can water decrease the usefulness of insulation
fur gets compressed when wet and doesn't insulate anymore
226
how does vasoconstriction promote regional heterothermia
decreases blood flow to skin
227
how do countercurrent heat exchange systems decrease heat loss
cool blood warmed by arterial blood as it returns to core
228
how does shivering counteract heat loss
heat production by cold induced involuntary muscle contraction
229
what is the purpose of daily torpor
body temp, metabolic rate, respiration, and heat rate are lowered
230
what is seasonal torpor triggered by
food deprivation, short day length, low temps in environment
231
what are the 3 phases of seasonal torpor
rapid entry, prolonged period, rapid arousal
232
how do shallow hibernation and profound hibernation differ
shallow: hibernation for a short period
profound: hibernation for a long period
233
what are the 2 types of arousal
alarm- ambient temp drops beyond animal's ability to compensate
periodic- absence of external cues
234
how does non shivering thermogenesis work
metabolic heat produced by metabolizing fat
235
what are some temperature regulation methods used by bats
heterothermy, hibernation
236
what are other ways mammals deal with cold environments
migration
237
what is behavioral thermoregulation
using the environment to warm up or cool down
