Exam 3 Questions

Question 1

Know the Geologic Time Scale

Answer 1

ok

Question 2

Describe the Dino Wars. Who were the main players? What good came out of it?

Answer 2

Othniel Charles Marsh
Edward Drinker Cope
Friends to rivals, bombed each others sites
Benefits: sparked public interest -> 136 new discoveries, boom in North America

Question 3

What was the first dinosaur ever named? How was it described at the time? How did they think it lived?

Answer 3

Megalosaurus
Described as a giant reptile, thought to walk on four legs.

Question 4

Describe the reptile categories based on temporal fenestra and give examples of each. What is the
function of reduced temporal fenestra?

Answer 4

Anapsids, synapsids, diapsids, euryapsids. Reduced temporal fenestra lightens weight and provides attachment points for muscles.

Question 5

Describe Anapsids, Synapsids, Diapsids, and Euryapsids. What is the difference? Give examples of each.
When did they appear in the fossil record? What are therapsids?

Answer 5

Anapsids: 0 opening- turtle Perm
Synapsid- 1 opening- mammals Carb
Diapsids- 2 openings: reptiles, crocs Carb
Euryapsids: 1 opening, lost one, sauropods. Perm.

Therapids: basal mammals, mammal-like reptiles.

Question 6

Describe the two the two major clades of Diapsids (Lepidosauromorpha and Archosauromorpha). How
are they different? Give examples of each. When did they evolve?

Answer 6

Lepido:
- mosasaur, snakes, lizards
- mobile skulls and extreme loosening of skulls to swallow prey. Tr- rec

Archo:
- Perm- Tr
- Basal form of triassic archosauria. Protosaurous, rhyncosaur, trilophosaurid, Lack of notochordal canals

Question 7

What is a key characteristic of the Archosauria? When did the first true archosaurs evolve? When did
most archosaurs go extinct?

Answer 7

Opening on snout just ahead of eye- anorbital fenestra. Early Tr- Late Tr.

Question 8

Describe the clades of Archosauria. What feature is used to distinguish
between the clades?

Answer 8

Differentiated by Ankle Bands
Curotarsans
- Sprawling, semi-erect stance, larger, outwards ankle, many die before Jr

Ornithodira
- Smaller, mesotarsal ankle, erect stance

Question 9

Describe the Permian-Triassic Extinction Event (severity/causes) and how it shaped the world for the
diversification of reptiles.

Answer 9

• Large igneous province. Siberian traps flood basalts
  Covers 7 mlilion square km
  2 million years of eruptions, spans permian-tri boundary
  changed ocean chemistry and circulation- anoxic
  changed atmospheric chemistry

Killed a whole bunch of creatures, opening up niches for dinosaurs to fill

Question 10

Describe the Cretaceous-Paleogene Extinction Event (severity/causes) and how it affected the nonavian
dinosaurs, marine reptiles, and flying reptiles

Answer 10

Volcanism and meteorite went KABOOM mother fuckers. L to the oceans too, cause they become anoxic AGAIN. Big boys died because starvation and bad climate. Little guys survived because they could burrow.
66ma
stepwise extinctions

Question 11

When did the earliest definitive dinosaur evolve? What are the two universally accepted diagnostic
characters that pertains to all dinosaurs? Describe the first dinosaurs of the Carnian Stage.

Answer 11

245ma (footprints)
Body fossil
- 230mya
South America
Perforate acetabulum- an opening in the hip socket of the pelvis
Parasagital stance (not completely dinosaurian): femur position in socket and ankle joint, efficient running locomotion. Mesotarsal joint specialized to move back and forth.

Carnian stage -235-229 mya
Insectovores, d

Question 12

What is
the Carnian pluvial episode and how did it influence the evolution of the first true dinosaurs?

Answer 12

232 mya
- volcanism, global climate change from dry- humid- dry
- extinctions of nondnios and amniote herbivoores
- new niches open for dinos. explkoded.

Question 13

How are Pterosaurs and Dinosaurs related? What was the time range for Pterosaurs? What are the
features that all Pterosaurs share?

Answer 13

They’re both Ornithodirans
Late Tr-K
- Flight
- Social
- Reptiles
- Many sizes
- Horny or feathered.
- Large brains, hollow bones
Warm blooded, well developed optic lobes
- Narrow membrane attached to modified 4th finger and thighs
Coastal/marine predators
- Ancestor unk

Question 14

Describe the 4 main pterosaurs highlighted in class. When did they evolve? What features set them
apart from each other?

Answer 14

Rhamophorhynchus
- Tr- L JR
- basal
- long tail, stiffened with ligaments
- tail ended in soft tissue tail vane
- needle-like teeth angled forward to catch fish

Dimorphodon
e Jr- K
Two kinds of teeth
- sharp front, flat back
- Closely related to rham
- 4 foot wingspan
- Short body large head
- Most time on groun

Pterodactylus
-lJur -K
- First to be named and discovered
Generalist Carnivore
compact body, long neck and skull, small tail
social

Pteranodon
L K-K
Large crested head
20-25 foot wingspan
weighed 25 pounds
bipedal, slow
soaring animal
scooplike beak

Late K
- Aztec winged serpent god
winged 11-40 feet
large, slender hind legs, long neck, short tail, large eyes, slender beak
Social, hunted in groups

Question 15

What are the two great clades of dinosaurs. How can you tell the difference?

Answer 15

Ornithiscians
- bird like pelvis, herbivores
- pubis runs posteriororly along the lower limb of the ischium

Saurischians
- Pelvis like a lizard
- pubis directed anteriorly and slightly downard
- more primitive pelvis in tetrapods

Question 16

What makes a Saurischian a Saurischian? What are the two types of saurischian dinosaurs?

Answer 16

Well developed grasphing hands and powerful feet
long fingers
thumb-graphsing
tight, articulated mtatarsals
- Sauropoda and Therapoda
Sauro-Long necked herbivorous
therapoda- Toothy carnibores and omnivores

Question 17

When did Theropods evolve? Describe the features that the nonavian theropods all shared (excl. birds)

Answer 17

L Tr
- Hollow bones, 3 toed limbs.
First all carnis, later developed more
All continents except Ant
- <1m- >15m in length
- Mostly all predators: claws, bipedal, fast, hollow bones
- Digitgrade stance
- Jr-> Birds
Smart
3 fingered “hands” primitve 4 fingers

Question 18

What is a digitgrade vs a plantigrade stance. Which dinosaurs had which stances?

Answer 18

Digitigrade- on it’s front toes, it’s digits
plantigrade- on the heel

Question 19

Describe the bite of toothed theropods. Describe their teeth. What can their teeth tell us in terms of
diet/way of obtaining food?

Answer 19

Velociratpor teeth: Puncturing and slicing: sliced like hacksaw blades

tyranno: Bulbous teeth and rounded serrations, weaker cutting, crush bone, greater bite power

allosaurus: slash and tear-> thin teeth and lightly built skull

Jaw joint a tthe level of tooth row, like scissors.

Question 20

Five main theropods were highlighted in class to compare their teeth, lifestyle, and features. Describe
when each evolved and features of each.

Answer 20

Allosaur
Slash and tear-> thin teeth and lightly built skull

Late Jr,

12 m
- 2000kg
- dagger esque teeth w serr edges, 5-10cm long and curved back
pack hunting
- large, powerful legs, small hands, long tail,
most abundant pred in Morrison Fm

Coelophysis
Late Tr

• 2-3m
• 27kg
• Teeth are small and sharp, serrated on anterior and posterior
  Grasphing claws
• speed and agility
• social groups and flocking
  -overruled by large reptiles
• hollow limb bones

Yutgrannus
Early K
7.5m
1100 kg
tyranno group
- 3 fings, long arms, shallow crest, short horns
- feathers
- area cool in early K
- china
- Packs?

Tryannosaurus
Late K
- 12m
- 7000kg
- teeth: 60 saw edged bone crushing, pointed 8 inch teeth
- 3x bite force lion
- skull >5ft long
- good smell, sight, hearing
- maybe social
- 68-66 ma

spinosaurus
Late K
14m
7400 kg
Smooth and cone shaped teeth
- fish eater
- sail 1.5 m
- tidal flats and marsh area
- 99-93 mya
- narrow snout with notches
- short legs, paddle like tail

Question 21

What would be the advantage of loss of teeth in the theropod group? Describe the two main edentulous
theropods highlighted.

Answer 21

• Ornithomimosaurs and Oviraptorsaurs
• less incubation time
• easier eating
• lighter birds

Ornithomimosaurus
Late K
- No teeth
- Beak
- Gratroliths
- Small skulls, long legs
Herbivores
hook-like hands
social
featheres

Oviraptor:
2m, 20kg, beak late k
short skull w well developed jaw muscles
brooding
feathered
found in mongolia

Question 22

Describe the different senses of theropods. Good/poor? How smart were they?

Answer 22

Sights: giant eyes, good vision
Hearnig: enlarged inner ear cavity-> low freq
Brain: smarter than dog or cat, possibly similar to chimp
Smell: large olfactory bulbs
color: melansomes: organelles w/different shapes and sizes for color
Feather: insulation, protection, camo, display, sensory

Question 23

Describe the evolution of feathers and what melasomes can tell us about their appearance. What were
the functions of the first feathers and coloration? Which diapsids had feathers?

Answer 23

Started out patchy and thin but some grew full pllumage as time went on.
melansomes: organelles w/different shapes and sizes for color
Feather: insulation, protection, camo, display, sensory

Archaeopteryx and deinonychus

Question 24

Six theropods were highlighted in class to show the intermediate forms between birds and nonavian
theropods. What were they, when did they evolve, could you describe them?

Answer 24

Nothronychus
Late K
- 5.3m
8-1200kg
crown shaped weak serrated teeth
herbivoer
pot bellied
big hands with 12 inch claws
shorter tail
partial omnivore

Archaeopteryx
Late Jr
0.5m
cone like teeth
feathers
ate small creatures
diurnal
sharp teeth, long bony tail
black

Confusiusornis
Early K
0.3m
0.5kg
beak
short tail
large claws
prim skull
large humerus

Utahraphtor
Early K
- 5.5m
350 kg
Lots of sharp, pointed teeth. Ate bigger prey. Ambush
Largest dromoaesaur
stockier
intelligent
feathered

Deinonychosaurus
Early K
3.4m 100kg backwards curving teeth
Small, carniv, large scicle talon on the 2nd toe
shorter leg bones
long stiff tail
feathered
paravian

Velociraptor
K
1.6m, 7kg, sharp, pointed teeth
solo hunting, clutching claws
birdlike hinged ankles, wish bone, forward toes
fine feathers, arm too short to fly
good smell
24 mph, intelligent

Question 25

When did Prosauropods evolve/disappear from the fossil record? Describe the key features that they all
share.

Answer 25

Primitive form of sauropods
Long neck, small head long tail, barrel shaped
distinctive mobile thumb and powerful claw
primitive leaf shaped teeth
gastroliths
herbiv
EJur/late Tr- EJur

Question 26

Describe the evolution of the nares and other
features in the skulls of the sauropods. What do we know about their eggs and nests? Did they
practice parental care?

Answer 26

skull nares migrate over time from tip to up
not chewing

LArge, returned to nesting grounds shallow trops, 15cm eggs, 15-34 per nest, abandoned, grew 12000 pounds a year, sexually mature at 20

Question 27

When did Sauropods evolve? Describe their key features. What are some specialized features in their
body plan that helped support such a large animal?

Answer 27

eJ- lK
Largest animals
long necks, small heads, not intelligent
non occluding teeth in front of mouth
obligate quadrapeds
teeth changed form
leaf shaped-> spoon shaped
limbs-> rigid columns
sexually dimorphic
plantigrade and digitgrade
tail did not drag
air sacs

Question 28

Stepping through the Sauropod groups from the Middle Jurassic to the end Cretaceous, what were the
main genera highlighted in class? How did they differ from each other? (Seven were highlighted).

Answer 28

Prosauropods (TR- LJr)
-Primitive forms, long necks, small heads,
barrel-shaped bodies, long tails
* Front limbs < hind limbs, suggesting
primitive bipedality
* Distinctive, mobile thumb with powerful
claw
* Primitive “leaf-shaped” teeth
* Gastroliths, indicating food processing in
the stomach
* Probably herbivorous

Eusoropoda

• More primitive
  characteristics
• Still large and
  quadrapedal
• All sauropods
  descended from
  this basal group

Diplodocoidea
Extremely elongate, even
gracile sauropods
* A single narial opening at the
top of the skull
* Rows of thin, chisel-like teeth
like a comb; restricted to the
front of the jaws
* Forelimbs shorter than
hindlimbs
* Whip-like tail, living in herds,
and big size gave protection

Neosauropoda

Macronaria
Have a large,
retracted narial
opening on a
robust, stout
skull
* Long forelimbs
and shorter tail
compared to
the Diplodocids
* Stoutly built

Camarasaramorpha
Ate tough plant material –
more spatulate (less thin) teeth
than diplodocids
* Distinctive cranial profile with a
blunt snout and an arched skill
that is square
* ‘Chambered lizard’ referring to
hollow chambers (plaurocoels)
on its vertebrate
* Only moderate length neck by
sauropod standards

Titanosauria
Largest (heaviest
and longest)
animal (marine or
land) of all time –
60 metric tons!
* Survived until the
K-Pg extinction

Question 29

What makes an Ornithischian an Ornithischian? Describe the three 3 sections that the skull is divided
into. What is the rhamptotheca and the diastema? Cheek teeth? What is the predentary and the
coronoid process?

Answer 29

Bird-like pelivs
eJr- K
Predenstary bone, unpaired extension of lower jaw
developed large stomach and intestional region
chewed food, cheeks
may have been primitive feathered
skuyll 3 sections
- beak: rhamoptotheca (inscisors)
- diastema (middle part, gap, toothless)
- Cheek teeth: back of skull grind down food
expansion of coronoid process

Question 30

When did the earliest basal ornithischian show up in the rock record? Which one was highlighted in class
and why do scientists think it is a basal ornithischian?

Answer 30

Late triassic
Pisanosaurus from the late Triassic,

Question 31

Describe the Thyreophora. When did the earliest appear and what features did they share?

Answer 31

Dermal armor or body plates on the back of the body.
All share: dorsal rows of dermal armor
Earliest in Early Jurrassic

Question 32

Describe features of the Stegosauria. What are the functions of the plates on Stegosaur backs? How did
they defend themselves? What can their teeth tell us about their diet? How smart were they?

Answer 32

9m
2000kg
- browser
- northern hemisphere
- quadraped
- solitary
- front< back legs
- dramatically sloping profiles
- not smart
- liesure
- spiked tails
- plates could have been for cooling or display, used to think defense
- weak jaws but chewing teeth
Late Jr

Question 33

Describe features of the Ankylosauria. How did they defend themselves? Describe the difference
between the two anklyoauria families.
en

Answer 33

Ankylosauridae and Nodosauridae
- wide bodies
- gut fermentation
- grinding teeth
- large throat bones and strong tongues
- low brosers
- armored skulls
- inset teeth
- 5m

Ankylo:
- tail club
triangle head
squamosal horns prominent
heavy build
head down Mid Jr

Nodosaurids
late jr
no tali club
should spikes
elongate head
long snout
powerful shoulder muscles
more gracile
head not angled down

• slow, solitary,

Question 34

What two dinosaur groups are included in the Marginocephalia? When did they evolve and what
features do they all share?

Answer 34

Pachycephalosauria:
Ceratopsia:
Late Jr- Late K
all bear a ridge or shelfe of bone on back of skull
many shapes and sizes
N hemisphere during K

Question 35

Describe the Pachycephalosaurs. When did they evolve? What are their key characteristics? What is the
function of the thickened skull?

Answer 35

Late K
- teeth and abdominal regions large
bipedal ornithscians with thickened skull roofs
peg like teeth
small thamphotheca
- typical brain
- enlarge smell
- back half angled downward brain
- thickened skulls for rams, secual display, or something else?
3,
45kg
omnivorous?
NA
social behavior

Question 36

Describe the Ceratopsia. When did they evolve? What are their key characteristics? What is the rostral
bone? What is the function of the horns and frills? Describe their dental battery and diet. Did
ceratopsians practice parental care? Describe the three ceratopsians highlighted in class.

Answer 36

LJr- K
N hemisphere
Quadrupeds
thick hooves
6-7 metric ton tanks
hooked beak skulls
rostral bone
horns
frill
herd
chewer
not girthy
fairly quick and intelligent

Psittacosaurus eK
- 2m 50kg
beak
round skull unique rostral bone, flared cheek bones
melasomes
2 or 4

Triceratops late K
9m
5500kg
horny beak, dental battery
smark
parental care
horns

Question 37

What dinosaurs are included in the Ornithopoda? Describe their key features. Why the development of
the ossified tendons? Describe their legs and digits. What did they eat? Describe their Pleurokinetic
skull. Describe their complex behavioral habits and evidence for. Why did these features evolve?
Did they practice parental care?

Answer 37

Iguanodon, Hadrosaurids (duck-bills) Middle Jr- end K
- Cows of mesozoic
- all herbivores
- numerous, diverse, everywhere
- early 1-2m later 15m
- long tail, muscular, strengthened by ossified tendons
- horizontal
- powerful hindlimbs
- fairly quick when springting

Gracile forelimbs
- herbivores
- beak, diastema, cheek teeth, inset row, bacterial fermentation
- smart
sexual display for skull
arched snouts, low broad bump on head, traveled in herds
some htachlings were instant travelers, some weren’t. parential care shown.

Question 38

Five ornithopoda dinosaurs were highlighted in class. What were their main features, when did they
evolve, can you describe them?

Answer 38

Orodromeus
- 2m
-50kg
- horny beak
- grinding cheek teeth
- small, bipedal, Na, burrowing

Camptosaurus
- Late Jr
- 5m
1000kh
- beak and teeth
- heavy
- no thumb spike
- 2 or 4 legs

Hadrosaurids
- Late K
- 9m, 3400kg, large bipedal
- bipedal
- duck billed
- cropped vegetation with beak
- large
- crest on head
-reduced 1st and 5th digit hands

Iguanodontidae
- Early K

• 10m
• 4000kg
• chewing teeth and horny beak
• long tongue
• four limbs or two
• thumb spike (1st digit)
• 5th digit opposable pinky

Question 39

Understand the two hypotheses surrounding how birds developed flight

Answer 39

Ground up,
Tree down.

Question 40

Know what features of the chicken we used comparative anatomy on, and how those features informed
our classification of the chicken

Answer 40

Enlarged Scapula, furcula, keeled sternum, pygostyle, pelvis similar to ornithischian but is saurischians, clavicle, femur, sternum.

Question 41

Describe Herrerasaurus, Eoraptor, and Plateosaurus and how they help us understand initial
sauropod evolution.

Answer 41

Herrasaurus
Prosauropod
lTr
3m, 350kg, flexible joint in jaw for sliding to bite, serrated teeth
carniborous but preyed on
one earliest fossilized
strong bipedal, long feet, short thighs, swift runner
basal- traits from arch

Eorapotor
L Tr
Prosaur
1.7m, 10kg, small razor teeth, omnivore
Small, lightly built, basal,
biped, fast, five digits on hands, humid, warm

Plateosaurus
L Tr
7m
4,000 Kg, grinding Teeth, horny beak
2 or 4 legs
5 fingers, large thumb
herds