test 2 Flashcards
(198 cards)
1
Q
definition of A biological species
A
a group of individuals
that could interbreed in
nature and produce
fertile offspring
2
Q
Darwin figured out why species change over time, but….
A
he did not know how
3
Q
who created Linnaean Taxonomy
A
Carolus Linnaeus
4
Q
When a similar anatomical structure in
two different organisms can be traced
back to single original structure in a
common ancestor, we call it a
A
homologous structure
5
Q
analogous structures
A
features look similar because they serve a similar function
6
Q
analogous structures are an example of c__________ evolution
A
convergent
7
Q
independent evolution of similar structures in
groups who are not closely related.
A
convergent evolution:
8
Q
what is Linnaean Taxonomy?
A
Hierarchical system ranks groups of organisms (taxa; singular-taxon) into successively
smaller categories
9
Q
Large groups are identified by _____,_____features.
Smaller groups are defined by more _____,_____ features
A
broad, general & specific, unique
10
Q
Lineus was a creationist or evolutionist?
A
creationist
11
Q
how did lineus develop his classification
A
He developed his classification
system based on how similar organisms were to one another. The more features two
organisms shared, the more closely related they were assumed to be.
12
Q
definition of natural selection
A
The struggle to survive + the natural variability among individuals results in some individuals
being more likely to produce offspring. These individuals are more successful at passing their
traits to the next generation.
13
Q
what animal did darwin study to formulate the theory of evolution
A
finches in the Galapagos Islands
14
Q
what are phylogenetic systematics and what do they do?
A
evolutionary
trees
method to classify animals into
groups and to understand how those
groups are related to one another.
15
Q
how do we understand how closely related creatures are using phylogeny?
A
using characteristics (observable features)
16
Q
we can use specific characters to determine within species not between species t/f
A
true
17
Q
diagnostic features
A
distinctive and unique characters which define a taxon
18
Q
Cladograms
A
branching diagrams that show hierarchies of diagnostic characters
19
Q
what do cladograms depics
A
depict a hypothesis of how two organisms are related to each other and are key to
understanding who’s related to whom
20
Q
cladogram node
A
where the characteristics they share are listed and a split off point on the diagram
21
Q
does order in a cladogram matter
A
no
22
Q
what does a short red bar in the cladogram mean?
A
shows that character 1 evolved before the common ancestor of A, B and C. This means that taxa A, B and C all inherited this feature.
23
Q
when is the cladogram most correct?
A
The cladogram that is the most correct is the one that does not change when new
characters are added.
24
Q
parsimony
A
that the simplest explanation is often the best. e.g. The most robust (NOT ‘correct’) cladogram is often the one with the fewest evolutionary steps.
25
primitive charaters
Characters that appear low on the cladogram
26
derived character
a trait that arose in the most recent common ancestor of a particular lineage and was passed along to its descendants
27
Early ancestors of vertebrates did not have a vertebral column. They had a _______
and the name of this creature was _____
flexible notochord
Pikaia
28
The first animals to develop a vertebral column did not have ______
jaws
29
the first animals with a vertabrete collumn were_____
jawless fish
30
gnathostomata meaning
gnathos = jaw; stoma = mouth
31
osteichthyes meaning
os = bone, ichthys = fish
32
who evolved first, gnathostomata or osteichthyes
gnathostomata
33
Sarcopterygii meaning
lobe finned fish
34
did Sarcopterygii evolve after osteichthyes?
yes
35
what evolved after limblike fish?
tetrapods
36
how did primitive tetrapods evolve to become more efficient on land
The evolution of a membrane called the amnion in eggs allowed the amniotes to become fully
terrestrial and prevent the eggs from drying out
37
synapsids feature
eveloped a single pair of openings
behind the eyes
38
diapsids feature
developed two pairs of openings behind the eyes (temporal openings)
39
monophyletic group
a group of organisms that includes a
common ancestor and all its descendants
40
what was the Dimetrodon
mammal-like reptiles that are misidentified as dinosaurs. they are neither dinosaurs nor mammals, but are synapsids
41
dinosaurs are synapsids or diapsids?
diapsids
42
issue with the Linnaean class Reptilia
classified animals based on them being cold blooded which contradicted with avian and non-avian dinosaurs
43
now, Linnaean class Reptilia includes all the ______
diapsids
44
the 2 Diapsids clades
Lepidosauromorphs and Archosauromorphs
45
Archosauromorphs features
have longer vertebrae in the neck which overlap to provide
support for longer necks.
46
Lepidosauromorphs
have short, non-overlapping vertebrae in the neck.
47
A subset of the archosauromorphs—the archosauria—have ________
additional openings in front of
the eyes called antorbital fenestra
48
two groups of Archosauria
Crurotarsi and Ornithodira
49
Ornithodira group features and animal examples
upright stance, Pterosaurs, birds, and dinosaurs
50
Crurotarsi group features and animal examples
a sprawling stance, crocodiles
51
clades in Ornithodira
Pterosauria and the
Dinosauria
52
separate evolution of flight in pterosaurs and birds is an example of
convergant evolution
53
Dinosauromorphs achieved a world-wide distribution. How?
singular supercontinent, Pangea
54
based on dinosauromorphs most closely related to dinosaurs, the primitive walking condition of dinosaurs was _____
bipedalism. quadropeds were then later evolved
55
All ornithodirans have an upright
posture with the hind limbs
positioned ________. Motion is limited to ________
directly underneath the
body, front-to-back
56
Dinosauromorphs also exhibit
digitigrade posture, meaning
standing on the
"balls of the feet" allowing for a
longer stride and short bursts of speed.
57
The dinosaurs (Dinosauria) are a subset of Dinosauromorpha with some minor
modifications to some _________
bones.
58
bone differences between Dinosauromorpha and dinosauria
stronger humorous and Perforate acetabulum
59
how can we tell dinosaurs had large muscles
large muscle attachment scars
60
all birds are ______, but not all dinosaurs are ____
dinosaurs, birds
61
possible oldest record of dinosaurs were ______ located in _______ and ________, ______ MYA
footprints, south america & europe rocks, 242-237
62
in what continent was the oldest dinosaur found?
south america
63
what can be said in contention to the theory that dinosaurs started off in south america
rocks that preserve fossils well are very rare during that time period and there could be a lack of preservation that leads to us not being able to find dinosaurs somewhere else
64
evolution and dispersal took place
quickly after the first appearance of
dinosaurs t/f
true
65
how does speciation occur
when a group within a species separates from other members of its species and develops its own unique characteristics
66
can species interbreed after speciation has occurred?
no
67
morphospecies
group of individuals that have some
reliable characters distinguishing them from all other species
68
The problem with defining morphospecies
we can’t often tell if the observed variation is
due to individual variation, sexual dimorphism, ontogenetic change (changes with age), or an
incomplete fossil record
69
medullary bone
bones that become spongy when a female dinosaur is pregnant in order to create eggs in turn lowering their own calcium density
70
Identifying age in the fossil record
-growth rings in bones and teeth
-Lack of fusion in the skull bones
-Young, rapidly growing bones are
spongier than adult bones
71
what are the three major groups of dinosaurs?
theropods, sauropodomorphs and or ornithischians
72
what bones make up the pelvic girdle?
Ilium
Ischium
Pubis
73
dinosaurs have been split into which 2 clades?
saurischian and ornithischian
74
saurischians description
Down and slightly forward. "lizard hipped"
75
ornithischians description
At least part of the pubis points
backwards. "bird hipped"
76
are birds Saurischian or Ornithischian
Saurischian, even though ornithischians are described as lizard hipped
77
Saurischians were typically carnivorous or herbivorous?
carnivorous
78
classic interpretation of the clade split
theropoda and sauropoda are saurischia
ornithischians are in Ornithischia
79
2017 interpretation of the clade split
Ornithischia and Theropoda are in Ornithoscelida
Sauropodomorpha is in Saurischia
80
what factors contributed to the 2017 clade split interpretation
- feather-like structure in Ornithischia and Theropoda but missing in sauropodomorphs and herrerasaurids
- primitive ornithischians look like theropods
- principle of parsimony: the simplest explanation is often the best. explains the feathers.
81
problems with the 2017 clade reinterpretation
- Both sauropodomorphs and theropods have pneumatic bones
- Carnivory would have to evolve twice
82
currently agreed upon clade split
Ornithischia, Sauropodomorpha, and Theropoda are three groups
83
do all animals chew their food
no, not all chew. i.e. snakes.
84
What are backward angled teeth used for?
grabbing on to prey and ripping their flesh while not letting them escape
85
animals that don't chew can also_____
wide gape
86
where does the jaw joint have to be for it to allow a wide gape
has to be at the same level as the tooth row
87
the 3 sections of the herbivore skull
cropping section, diastema and the cheek teeth
88
what is the cropping section of a herbivore's jaw
blade-like teeth that bite off chunks of food
89
what is the diastema in a herbivore's jaw
toothless gap for food manipulation by the tongue
90
what is the cheek teeth section of a herbivore's jaw
molar, a place for grinding down food into paste
91
adaptations for chewing
- coronoid process
- closely packed teeth with flat grinding surface
- teeth fit together tightly on top and bottom for efficient grinding
- inset tooth row to support cheeks
- jaw joint is above tooth row allowing for upper and lower teeth ti make contact at same time
92
how do carnivores break down food without chewing
material is easily digested by their stomach acids.
93
how do herbivores & omnivores break down food
- digestion begins with an enzyme in the saliva that helps break down carbohydrates
- have large barrel shape guts that accommodate long digestive tracts.
94
gastroliths
- small stones ingested by animals who do not chew
- help mechanically process the food
- can also be used as weight to provide stability
95
where theropods good chewers?
no, they share the characteristics of carnivores.
96
where sauropodomorphs good chewers?
no, their joint is on tooth line and teeth and long and spread out. teeth mainly used for puncturing.
had barrel shaped guts and used gastroliths
97
were ornithischians good chewers?
they were okay chewers
had the cropping section in the form of a beak, called rhamphotheca
jaw joint was below teeth row and allowed for upper and lower teeth to clamp down at the same time.
98
direct evidence for what dinosaurs
Coprolites
Cololites
99
what would cause a sauropod to feint?
rearing up and taking a tripodal stance
100
what would happen if sauropods breathed like us?
the long neck
would have contained a
bunch of unused air
101
how did sauropods breathe?
through a bird-like system where air followed a loop from an air sac to lungs to another air sac and out
some air sacs were held in the hollow bones
102
what did the pneumatic bones help the sauropods with?
kept the upper
skeleton light, and helped with breathing
103
3 reasons sauropods got so big
- light skeleton
- Small heads because they didn’t chew (no large chewing muscles/
attachment sites)
- Unidirectional respiration
104
what did sauropod size help with?
Long neck = efficient feeding without moving
More food = larger body size
Large body size = protection from predators
105
what was the evidence that pointed towards sauropods laying eggs?
nesting site discovered in patagonia that had eggs the size of soccer balls which would house babies the size of adult geese. this site had several layers of eggs.
Mothers either buried their eggs
and left the site after laying them
or communally guarded them
106
characters that make ornithischians a well-defined group.
- Predentary bone
- Toothless and roughened
tip of snout
- A narrow bone (called the
palpebral) that crosses the
outside of the eye socket
- Jaw joint set below upper
tooth row
- Cheek teeth with low,
subtriangular crowns
- At least 5 sacral vertebrae
Ossified (turned to bone)
tendons above the sacral
region/further along the
vertebral column
107
what 3 body features contribute towards ornithischians being herbivorous?
- Ribs flare widely = large gut region
- The predentary supported the beak
= cropping vegetation
- backward-pointing pubis may
have accommodated large gut
region
108
what 3 facial features contribute towards ornithischians being herbivorous
- Toothless, rough front tip
of the snout.
- A jaw joint that is
positioned below the level
the tooth row
- Triangular-shaped cheek
teeth with low crowns
109
name of biggest Ornithischia clade
Genasauria, a group defined by having great cheeks
110
on what basis is genasauria further split and into what groups?
how efficient chewing was in
each group.
Thyreophora and Cerapoda
111
description of Thyreophorans
dermal armor-
bony plates embedded in the
skin-along the back surface of
the body
stegosaur and ankylosaur
112
what is Cerapoda split into?
Marginocephalia and Ornithopda
113
description of Marginocephalians
group united by having a shelf of bone
extending over the back of the skull
triceratops
114
description of Ornithopoda
Iguanodon, “duckbilled dinosaurs,” and other
excellent chewers
115
what was the name of the dinosaur beak and what was it made out of
rhamphotheca, made out of the protein keratin
116
what could a dinosaur beak be used for
gripping, ripping, breaking
117
what are the bones that Thyreophorans have called?
osteoderms
118
is Amargasaurus a thyreophoran?
no, it does have protective structures, but they grow from the spine rather than being embedded into the skin.
119
how were Thyreophora with chewing and how were their teeth?
- they were okay chewers and used rhamphothecae (beak) to break up foliage and had strong jaw muscles
- teeth are small, simple, triangular, lack regular grinding surfaces and do not fit
together well.
120
how did the Thyreophora eat?
Heads were low to the ground, so ate ferns and cycads <1 m off the ground.
121
what are the two great clades of Thyreophora?
Stegosauria
Ankylosauria
122
features of Stegosauria
- Plates organized in rows down
neck, back and tail
- Long hindlimbs, short forelimbs
123
how were stegosaurus spines aligned, and what were they used for?
- aligned in rows
- used for defense. tail spikes called thagomizer and plates made it look bigger.
- display, to identify the sexes (sexual dimorphism)
- thermoregulation
124
Meaning of Ankylosauria
fused lizard
125
2 main groups of ankylosauria
- Ankylosauria
- Nodosauridae
126
difference between ankylosauria and nodosauridae
Ankylosauridae had a shorter head and a broad beak, armor plates, and tail spikes or knobs
while nodosauridae had a longer head, narrow beak and shoulder spikes
127
what does a broad beak say about feeding?
less selective to what they eat
128
what does a narrow beak say about feeding?
more selective
129
because they Had a small ratio of brain: body size, ankylosaurs were not very smart, but they had very good ________
smelling
130
Nodosaurids defend _____ first while Ankylosaurids defend ______ first
head, tail
131
what does Marginocephalian mean
edge head
132
what are the two main groups of Marginocephalians
Pachycephalosauria and Ceratopsia
133
Pachycephalosauria meaning
thick head lizard
134
what do recent studies say about the Pachycephalosaurias flat skull?
may just be juvenile forms
of adults
135
were the Pachycephalosaurs smart?
had unremarkable, typical
ornithischian brains, but:
Had a good sense of smell
136
evidence of Pachycephalosaurs head butting
- structure of dome is very dense
- bone fibres are perpendicular
- vertebrae are linked in a way that limits rotation
137
evidence against Pachycephalosaurs head butting
The skull cap of Stygimoloch contains a
network of canals for blood vessels. it could be a juvenile though and headbutting is only for adults.
138
Pachycephalosaurs features
- dome
- Canine-like teeth
- Knobby/spiny osteoderms on the snout/side of the face
139
why did Pachycephalosaurs not preserve well in north America?
because there was a lot of water and movement before foscilization
140
Ceratopsia meaning
horn face
141
Ceratopsian features
- rostral bone at the snout
- hooked beak
- jugal horns on cheeks
- frill
- hooves on toes
- facial horns
142
what were primitive forms of Ceratopsians like?
smaller, bipedal and not facial horns
143
besides defense, horns and frills could be used for
- Display
- ritualized combat
- defense of territories
- maturity
- species identification
144
did ceratoptions take part in herd behavior?
yes
145
Ornithopoda were the ________ of the _______ and why
cattle of the cretaceous
because they abundant, herbivorous and diverse
146
ornithopod meaning
bird foot
147
ornithopod features
- jaw joint below tooth rows; made them best chewers
- came in different sizes
148
major groups in ornithopoda
Iguanodontia, Ankyllopollexia and the Hadrosauridae
149
Hadrosauridae features
- rows of teeth constantly
replaced
150
the 2 hadrosauridae groups
- Hadrosaurines (solid crested), mightve had air bags on their nose
- Lambeosaurines (hollow crested), with a crest that extends upwards
151
meaning of Theropoda
beast foot
152
general characters of theropods
- Knife-like teeth (thin, curved
backwards, serrated)
- Extra openings in front of the
antorbital
- Large hands with grasping ability
153
what lineage of dinosaurs do birds come from?
theropods
154
what did the hollow bones help the theropods with?
air sacs which made them efficient breathers
155
what is the global distribution of theropods?
they can be found everywhere
156
description of theropod tracks
slender toes, more v-shaped, longer foor
157
what is a furcula, what does it do and what can it be found on?
- fused clavicles (collarbone)
- strengthens the thorax and helps in flight
- birds and theropods
158
coelophysoidea Theropoda description
small to medium carnivores
159
ceeratosauria Theropoda description
a bucket to put the theropods that did not match
160
megalosaurus Theropoda description
inflexible tail
161
megalosaurus: Spinosaurus Theropoda description
crocodile like forms
162
allosaurus Theropoda description
3-fingered meat eaters
163
tyrannosauridae Theropoda description
trex were 2-fingered meat eaters
only evolved after extinction of allosaurs
164
compsognathidae Theropoda description
small carnivores
some had feathers
165
ornithomimisauria Theropoda description
bird or ostrich mimics
have wings that were used for display or courtship
166
therizinosauridae Theropoda description
long-clawed herbivores
semi-lunate wrist-bone that allows bending wrist back
167
oviraptorosauria Theropoda description
parrot like skull
semi-lunate wrist-bone
168
alvarezsauridae Theropoda description
small insectivores
169
what does eumaniraptora Theropoda include
sickle like claw
small bodied (e.g. velciraptor)
last know step is archeopteryx
present day birds
170
theropoda evolutionary trends
- decrease in body mass
- addition of feathers
- change to omnivores or herbivores
171
what did large neotheropods typically have?
elaborate head ornaments
172
Direct evidence for what dinosaurs ate:
Coprolites and Cololites
173
what are Coprolites
fossil poop
174
what are Cololites
fossilized gut contents
175
Indirect evidence of what dinosaurs ate:
- Assemble all of the known fossils from an area. The carnivores likely ate
the herbivores, the herbivores likely ate the plants.
- Look for teeth marks on bones.
176
definition of sauropodamorph:
lizard-foot-form
177
where were the extra neck vertebrae of the sauropods located?
in front and behind the sacrum (hips)
178
sauropods lived for the entire time of the dinosaurs and were abundant on every continent t/f?
true asf
179
what physiological changes happened to sauropods over time?
necks become longer, heads become smaller, hind legs and
front legs become more equal in length
180
rise of the sauropodomorphs parallels the rise of what form of vegetation?
tall gymnosperms (delicious seed-bearing plants).
also were the first to take advantage of tall plants
181
characteristics of sauropods' eating and digestive system
- Bad chewers
- Large animals with small mouths
so must have always been eating
- Digestive system probably a
continuous, low-speed conveyor
belt of food
- claw may have aided in ripping
vegetation into smaller pieces
182
what sauropod might have been larger than the argentinosaurus and why might evidence be weak for it?
the Patagotitan, but all estimates
are made on very incomplete skeletons
183
what feature did sauropod vertebrae have that reduced their weight?
pneumatic bones with cavities and openings kept the upper skeleton light
184
features of sauropod skull
- Extremely small
- Delicately built
- Full of large openings
- Very light because it goes at the end of a long neck.
185
what are the 2 Sauropoda groups and what are they split on?
Diplodocoidea & Macronaria, split on placement and size of nostrils
186
Diplodocoidea features
- fully retracted external nares
above eyes
- peg-like teeth along front of jaw
forming tooth comb. like a brush in the front of their mouth
187
Macronaria features
- Nares as large as or larger than
orbit
- Nares move towards top of skull, creating bump on head
- Shortening and elevation of skull,
indicating more powerful biting
force
188
Does the fleshy nose and bony nose have to be located in the same area and what effect did this assumption have on sauropods?
no, they do not have to be in the same location.
before paleontologists knew this, they assumed the sauropods would function as snorkels.
189
what evidence convinced scientists that sauropods lived on land?
- water pressure too high to allow for breathing
- robust hips, dense/pillar-like limbs, and weight-bearing feet suggest life on land
- Sauropods are found in a range of environments from swamps to lakes to
coastal areas
190
features of sauropod locomotion
- Narrow trackways, although bodies are very wide
- Tail was held off the ground when walking
- The youngest of the group would walk in the middle
191
why was the trunk theory wrong?
- trunks are needed when necks are short
- unlike elephants, sauropods have little fascial nerves
- probably had cartilage, blood vessels and other soft tissues that made up the nasal cavity
192
where were sauropod fleshy noses most likely located and why did paleontologists come to this conclusion?
- fleshy nostrils further
down the face and closer to the
mouth than to the eyes.
193
4 methods of making a neck longer
- Increase the length of the individual
vertebrae
- Recruit vertebrae from the back into the
neck
- Increase the number of neck vertebrae
- combination of the above
194
what are Nuchal Ligaments?
elastic rope of connective tissue that ran down the neck and back to support the head so the muscles didn’t have to work as hard
195
Why did Sauropods have long necks?
so They could feed on tall trees.
196
what neck orientation did most sauropods have?
horizontal necks that helped them feed within 2-3m above ground and more efficient
197
physiological demands of a tall neck are?
high blood pressure to pump blood so high
198
Ankylopollexia feature
Ankylopollexians had specialized fingers
- The thumb (I) was conical and pointed
- rest were were tipped with hooves
