Lesson 1

Question 1

T/F
All large reptiles that are extinct are known as dinosaurs

Answer 1

false

dinosaurs have a very specific definition!

Question 2

the definition of a dinosaur is determined by anatomical details in the ______
eg

Answer 2

skeleton

eg air sinus present, hind legs: ankles move to tuck their legs underneath

Question 3

who invented the term ‘dinosaur’? When?

Answer 3

Sir Richard Owen
170 years ago
- no complete dino skeletons had been found at this point!

Question 4

bones had been found from 3 different dinosaurs at the time that Sir Richard Owen invented the term dinosaur. What were the 3?
- What were they previously described as?

Answer 4

megalosaurus, iguanodon, hylaeosaurus

• extinct giant reptiles

Question 5

What do megalosaurus, iguanodon, & hylaeosaurus all have in common?

Answer 5

• teeth that grew out of sockets (like modern crocodiles)
• erect limbs (like modern mammals, birds)

Suggested these 3 creatures were more related to each other than to any modern reptile, so created ‘dinosauria’ group

Question 6

___ are more likely to fossilize than other body structures

Answer 6

bones

Question 7

paleontologists look at what to determine how many dino species there were?
- also to understand how ecosystems changed through time and adaptations of each species

Answer 7

the skeletons

Question 8

______, or “long-necked dinos” include the largest animal that ever walked the earth

Answer 8

sauropods

Question 9

Which of the following was the largest sauropod?
- argentinosaurous
- diplodocus
- giraffatian

Answer 9

depends on the definition of ‘large’!

• gieaffatitan= tallest dino
• diplodocus= longest
• argentinosaurous= heaviest

Question 10

how is the weight of a dino estimated?

Answer 10

extrapolation based on comparison of limb proportions of the dino compared to those of large modern mammals whose weights can be measured directly

Question 11

Why is it hard to estimate how heavy a dino was based on its fossils?

Answer 11

• usually incomplete skeleton
• only includes bones, no organs/ muscles etc
• bones have been infiltrated w/ minerals= heavier
• some had air sacs, which would make them much lighter than an equivalently sized modern mammal

Question 12

the smallest dinos were smaller than a _____!

t/f
lots of these were meat eaters

Answer 12

chicken

true!

Question 13

t/f

humans and dinos have basically the same skeletons with the same bones in the same places

why or why not?

Answer 13

true!

because we’re all vertebrates, so have a common ancestor

Question 14

which of the following are vertebrates?
- humans
- sharks
- octopus
- snakes

Answer 14

all except octopus

Question 15

what are the openings for the eyes in a skull called?

Answer 15

orbits

Question 16

what are the openings for the nose in a skull called?

Answer 16

nares

Question 17

openings in the skull that aren’t for the nose or eyes are called _____, which means ____

Answer 17

fenestrae

window

Question 18

fenestrae are important for distinguishing between major _____ of _____

Answer 18

lineages of vertebrae

Question 19

the antorbital fenestra will be ____ (in front of/ behind) the orbit, and the laterotemporal fenestra will be ____ (in front of/ behind) the orbit

Answer 19

antorbital = in front
laterotemporal = behind

Question 20

where would the super temporal fenestra be located?

Answer 20

on top of the skull

Question 21

t/f

neck vertebrae are different from back vertebrae

Answer 21

true

Question 22

neck vertebrae are called ____
back=
hip=
tail=

Answer 22

neck= caudal
back= sacral
hip= dorsal
tail= cervical

Question 23

t/f dinos don’t have ribs in the rear portion of their body

Answer 23

false!
dinos had ribs all the way to their pelvis
- mammals are unusual and do not have ribs in the rear portion of our body

Question 24

_____ are “belly ribs” and are not found in mammals. They’re an adaptation for flexibility and posture

Answer 24

gastralia

Question 25

your arms and legs connect to the rest of the body via the ___ ____ - for arms: ____ ______ - for legs: ______ ____

Answer 25

limb girdles shoulder girdle hip/ pelvic girdle

Question 26

t/f the bones of different animals may take different shapes, but the same kinds of bones will be present

Answer 26

true

Question 27

give some similarities and differences between human vs tyrannosaurus arm bones

Answer 27

similarities: - same bones are present! humerus, radius, ulna, and metacarpals present in both differences - dino has bigger arm - dino only has 2 main fingers compared to our 5 - dino had large claws on fingers, while ours were replaced with fingernails

Question 28

do humans and dinos share the same leg bones? which?

Answer 28

yes! upper= femur 2 lower= tibia and fibula

Question 29

t/f Like most dinosaurs, all Tyrannosaurus walked on their toes and the soles of their feet were elevated off the ground.

Answer 29

true

Question 30

sacral vertebrae are fused to the ___

Answer 30

hips

Question 31

the first major division of dinos is based on the shape of the ___

Answer 31

pelvis

Question 32

What are the 2 groups called that divide dinos based on pelvis shape?

Answer 32

1. saurischia (lizard hipped dinos) 2. irnithischians (bird hipped dinos)

Question 33

did birds evolve from saurischia or irnithischians?

Answer 33

confusingly, birds evolved from lizard hipped dinos, not bird hipped dinos. = saurischia

Question 34

all dinos have __ pairs of bones that make up their pelvis

Answer 34

3

Question 35

what's the largest bone in a dino body?

Answer 35

ilium (in the pelvis)

Question 36

explain the main 4 bones of the dino pelvis and briefly what they do

Answer 36

1. sacrum= fused to vertebral column, designed to support great weight 2. ilium= upper bone (largest in the body). pull the leg forward and back 3. ischium= smaller bone beneath ilium: goes down and back 4. pubis: goes down and forward. different in saurischians vs ornithischians

Question 37

What's the easiest way to tell a ornithischian from a saurischian dino based on the pelvis?

Answer 37

the pubis bone: in ornithischians, the pubis reorientates itself so it's back beside the ischium. in saurischians, the pubis has a huge boot on the bottom to support weight

Question 38

The saurischians can be divided into 2 major groups:

Answer 38

1. sauropods (long-necked dinos) 2. theropods (very diverse!) - carnivores, herbivores, etc

Question 39

t/f all theropods walked on their front legs

Answer 39

false all theropods walked on their hind legs

Question 40

_____ were an early group of plant- eating dinos and were much smaller than their giant sauropod cousins (some were still massive)

Answer 40

Prosauropods

Question 41

Prosauropods - ___ heads and ___ necks - ___ hands - ability to stand and walk only on their __ feet - successful at first, but had a __ reign

Answer 41

small, long grasping hind short

Question 42

there are two key traits that distinguish all ornithischians from thischians:

Answer 42

1. ornithischians have a hip with a pubic bone that points backwards 2. ornithischians have a special bone in the lower jaw, called the predentary. No other animals have one. These adaptations were for a vegetarian lifestyle

Question 43

the backwards pointing pubic bones of Ornithischians resembles those of birds. Does this mean they're closely related?

Answer 43

No, it's an evolutionary convergence, so there is no close relationship

Question 44

how did the predentory bone help with herbivory?

Answer 44

helped to form a cropping beak in the front of the mouth= tool for slicing off plant stems

Question 45

how did the backwards pointing pubis give ornithischians an advantage as herbivores?

Answer 45

gave extra belly room for an enlarged digestive tract (plant matter is difficult to digest!)

Question 46

t/f ornithischians were all omnivores

Answer 46

false they were all herbivores

Question 47

what are the 5 main lineages of ornithischians?

Answer 47

1. duck-billed hadrosaurs 2. ceratopsians 3. dome-headed dinos (pachycephalosaurus) 4. stegosaurus 5. ankylosaurs

Question 48

ornithopods= ___-hipped dinos that typically walk on __ legs and are _____(herbivores/ carnivores)

Answer 48

bird 2 herbivores

Question 49

ceratopsians walk on __ legs and have ___ at the back of the head, made up from elongated bones from the back of the skull

Answer 49

4 frills

Question 50

what is a boss?

Answer 50

a bony mass - can be nasal, supraorbital, etc eg. pachyrhinosaurus has both

Question 51

t/f the dome-headed dinos had a very large brain

Answer 51

false the large head was just bone, not brain :( likely used the domes to recognize each other and/or headbutting

Question 52

stegosauria walked on __ legs, although their ___ legs were shorter than their __ legs

Answer 52

4 front shorter than hind

Question 53

what is the most distinguishing characteristic of stegosauria?

Answer 53

osteroderms= the plates/ spikes along the back --> formed from a special type of bone that forms in the skin

Question 54

ankylosauria are known as the "_____ dinos" and have ___-shaped skulls. They are covered in ___ of different sizes, and sometimes have a huge one at the end of the tail to form a ___ ____

Answer 54

armoured block osteoderms tail club

Question 55

t/f muscles, organs, and skin of dinos are never preserved, so we don't actually know the true appearance of any dino

Answer 55

false although organs etc decay much faster than bones, sometimes we can get an idea of appearance from well-preserved tracks with scales etc also, sometimes the body was covered with mud shortly after dying, so skin impressions were left before rotting away

Question 56

mummified dinos=

Answer 56

dino skeletons with lots of associated skin (rare!). large regions of skin hanging off the bones first found in wyoming in 1910 keratin (beaks, claws, etc) almost 'fossilized'

Question 57

integumentary structures=

Answer 57

The integumentary system includes the epidermis, dermis, hypodermis, associated glands, hair, and nails

Question 58

t/f sometimes integumentary structures revealed in the fossil record reveal an adaptation we never would've guessed a dino would have

Answer 58

true!

Question 59

t/f very few dino groups besides birds had feathers

Answer 59

false! many dino groups did eg. feathered velociraptor

Question 60

what is the impact of volcanic ash on fossilization?

Answer 60

like mud, it preserves fossils very well. however, it also alters the chemistry of the water, and bacteria can't live in it, so feathers, etc are preserved

Question 61

which of the following most likely had feathers based on evidence? - tyrannosaurus - edmontosaurus - stegosaurus - velociraptor

Answer 61

definitely velociraptor, probably tyrannosaurus too

Question 62

for which group do we currently not have any skin impression?

Answer 62

pachycephalosaurs

Question 63

do both ankylosaurus and stegosaurus have osteoderms?

Answer 63

yes!

Question 64

what might be some benefits of having osteoderms?

Answer 64

-storing calcium (eg in sauropods) - gathering heat from the sun (if the osteoderm was covered in skin/ blood vessels) - protection from biting/ clawing predators - to look good! (eg stegosaurus flaunting it) mostly as protection though

Question 65

scales, feathers, bristles, and osteoderms are called ______ _______

Answer 65

integumentary structures

Question 66

what are eumelanosomes?

Answer 66

an arrangement of pigment cells that determines feather color in modern birds. none= white long & narrow= black and grey this is a proxy to see what color dino feathers might've been!

Question 67

t/f evidence for dino colors of blue, green, and red have been found

Answer 67

false no evidence for those colors existing

Question 68

Do we have any idea what color dino skin might have been?

Answer 68

no can't use eumolanisomes for skin, only feathers

Question 69

what does osteoderm mean?

Answer 69

"skin bones" b/c these are bones that are formed completely within the dermis (lower layer of skin) we don't have anything like this!

Question 70

from a ______, or dino dropping, from a tyrannosaur, we have the remains of muscle fibers

Answer 70

coprolite

Question 71

the best evidence for soft anatomy of a dino comes from looking at the _____

Answer 71

bones - can see striations where the muscles attached to it

Question 72

____ are the descendants of dinos and ____ are the second cousins of dinos. Why is this useful in trying to understand muscles in dinos?

Answer 72

birds crocodiles if we find the same muscles attached to the same points/ bones in both birds and crocs, we can infer that those were the same muscles attached to those points in dinos

Question 73

how do we know what tyrannosaurus teeth looked like?

Answer 73

there are tooth imprints in bone (they were strong enough to bite through bone!)

Question 74

_____ has the strongest bite of any animal, alive or dead

Answer 74

t-rex

Question 75

compare the jaws/ bites of t-rex vs gigantosaurus

Answer 75

gigantosaurus had longer skull and lower jaw = less powerful bite than t-rex, but could close its jaws much faster