CHAPTER 1 - The Skeleton

Question 1

Palaeontology

Answer 1

the study of all prehistoric life.

Question 2

fossil

Answer 2

any preserved evidence left behind by a prehistoric organism. The word fossil literally means “dug up”

Question 3

Adaptations

Answer 3

are traits that have evolved to serve specific functions.

Question 4

4 Adaptations that Bones help animals to survive by serving four major functions?

Answer 4

1 - bones passively resist gravity and maintain an animal’s form
2 - bones provide a ridged framework for muscle attachment.
3 - bones provide protection and can also be major components of horns and other robust weapons
4 - bones store mineral reserves

Question 5

Vertebrates

Answer 5

are animals that have two special kinds of skeletal adaptations: skulls and vertebrae

Question 6

Vertebrae

Answer 6

are structures made primarily of bone and/or cartilage that surround a portion of the spinal nerve cord.

Question 7

The brain case

Answer 7

is a hollow chamber formed by multiple skull bones that houses the brain.

Question 8

Dinosaur skulls also have multiple pairs of large openings. Name the five

Answer 8

1 - The nares (singular: naris) are the pair of openings for the nostrils.
2 - The orbits are the pair of openings for the eyes.
3 - lateral sides of the skull are called the laterotemporal fenestrae
4 - fenestrae on the top of the skull are called the supratemporal fenestrae.
5 - antorbital fenestrae. The function of the antorbital fenestra is unclear. They may have simply been adaptations that made dinosaurs skulls lighter, or they may have also housed large sinus cavities that helped warm the air that dinosaurs breathed.

Question 9

centrum.

Answer 9

vertebra has a spool- or disk-shaped body,

Question 10

neural arch

Answer 10

Above the Centrum, which covers the neural cannel

Question 11

neural canal

Answer 11

is the opening in each vertebra, through which the spinal nerves run.

Question 12

Vertebral processes

Answer 12

provide attachment surfaces for muscles and sometimes provide articulation surfaces for ribs.

Question 13

Two common types of vertebral processes are

Answer 13

transverse processes, which extend from the lateral sides of the vertebrae, and spinous processes, which extend upwards from the neural arch.

Question 14

cervical vertebrae

Answer 14

Vertebrae (singular: vertebra) in the neck. Cervical vertebrae often have extra-large openings for blood and nerve channels and are adapted to support the weight of an animal’s head.

Question 15

dorsal vertebrae

Answer 15

Vertebrae in the back. Dorsal vertebrae often have tall spinous processes and large rib articulation surfaces.

Question 16

sacral vertebrae

Answer 16

Vertebrae in the hips. Because the pelvic bones serve as solid anchors for powerful leg muscles, the pelvic bones (later discussed in detail) are fused to the sacral vertebrae.

Question 17

sacrum

Answer 17

To further increase the strength of the hips, the sacral vertebrae are also fused with one another and form a single solid bone structure

Question 18

caudal vertebrae

Answer 18

vertebrae in the tail

Question 19

chevrons.

Answer 19

Underneath caudal vertebrae are bones. Chevrons protect a large blood and nerve channel and provide support for tail muscles.

Question 20

Discuss the difference between the ribs in animals and dinos

Answer 20

In dinosaurs, all dorsal vertebrae connect with ribs; however, in mammals, the dorsal vertebrae close to the hips do not. Also unlike mammals, some dinosaurs had gastralia, or “belly ribs”.

Question 21

Gastralia

Answer 21

are small ribs positioned across a dinosaur’s underbelly, underneath the ribcage.

Question 22

Tetrapods

Answer 22

animals that evolved from an ancient ancestor with four feet and four limbs. Most tetropods still have four feet and limbs, although some, like humans, have hands instead of front feet and some, like snakes, have lost their limbs altogether.

Question 23

The forelimbs of a tetrapod connect to the

Answer 23

pectoral girdle

Question 24

scapula

Answer 24

is the largest bone in each side of the pectoral girdle.

Question 25

The hindlimbs of a tetrapod connect to the

Answer 25

pelvic girdle, or hip bones

Question 26

The upper hip bone is called the

Answer 26

ilium.

Question 27

Below the ilium are the

Answer 27

pubis and the ischium.

Question 28

acetabulum

Answer 28

the depression or (as in dinosaurs) the hole in the pelvic girdle into which the hind limb articulates.

Question 29

Between the shoulder and elbow is the largest bone in the forelimb, called the

Answer 29

humerus.

Question 30

Between the elbow and the wrist are two parallel bones

Answer 30

called the radius and ulnaIn. In most tetropods, the radius is the thinner of the two.

Question 31

carpels

Answer 31

The bones in the wrist

Question 32

metacarpals.

Answer 32

The bones between the wrist and fingers

Question 33

Finger bones are called

Answer 33

phalanges

Question 34

Between the hip and knee is the largest bone in the hindlimbs, called

Answer 34

femur.

Question 35

Between the knee and the ankle are two parallel bones,

Answer 35

the fibula and tibia. The tibia is the bone that forms our shin.

Question 36

The bones in the ankle are called tarsals. The bones between the ankle and toes are called

Answer 36

metatarsals.

Question 37

There are two major groups of dinos

Answer 37

saurischians and ornithischians

Question 38

Saurischian dinosaurs are those that share an evolutionary ancestor that had a pubis that

Answer 38

extended downwards and forwards, towards the ribcage.

Question 39

Ornithischian dinosaurs are those that share an evolutionary ancestor that had both

Answer 39

special beak-forming bone in the upper jaw (called the predentary) and a pubis that extended downwards and backwards, towards the tail.

Question 40

“Saurischian” means “__”, and “ornithischian” means “__”.

Answer 40

lizard hipped and bird hipped

Question 41

Birds are part of a special group of saurischian dinosaurs that changed their pubis from

Answer 41

extending forward to extending backwards

Question 42

There are two major groups of saurischian dinosaurs:

Answer 42

sauropodomorphs and theropods.

Question 43

Sauropomorphs

Answer 43

large herbivores with elongated necks and relatively small heads.

Question 44

Prosauropods

Answer 44

were an early group of sauropodomorphs and were the first group of large-bodied herbivorous dinosaurs to evolve

Question 45

Sauropods

Answer 45

were a later group of sauropodomorphs. Many sauropods attained truly gigantic size, and the group includes the largest animals to ever walk the earth.

Question 46

Theropods

Answer 46

were bipedal saurischian dinosaurs that shared a carnivorous ancestor. Many theropods were carnivorous and have serrated
blade-like teeth and sharp hooked claws, but some were herbivorous and a few lack teeth altogether.

Question 47

The backwards extending pubis, which gives ornithischians their name, was an adaptation that

Answer 47

created more space in the ribcage. This extra space was probably filled by extra-large digestive organs.

Question 48

There are five major groups within the ornithischians:

Answer 48

ornithopods, pachycephalosaurs, ceratopsians, stegosaurs, and ankylosaurs.

Question 49

Ornithopods include

Answer 49

a wide range of dinosaurs that lack armor and that either walked bipedally all the time or assumed a bipedal stance when running. Many ornithopods are small antelope-sized dinosaurs, but some, like the iguanodonts and hadrosaurs, grew to be multi-ton giants.

Question 50

Iguanodonts

Answer 50

large ornithopods with a spike-shaped claw on each hand.

Question 51

Hadrosaurs are the famous

Answer 51

“duckbilled dinosaurs”. Hadrosaurs evolved late in the history of dinosaurs, but were highly successful

Question 52

tightly packed rows of small teeth in the rear of the Duckbill mouths. Together, these teeth form large chewing surfaces and are collectively referred to as

Answer 52

dental batteries.

Question 53

Pachycephalosaurs

Answer 53

were bipedal with short arms, unusually stout and strong tails, and armored skulls. pachycephalosaurs may have rammed predators or have butted heads with each other in competitions for territory or mating rights.

Question 54

Ceratopsians

Answer 54

Ceratopsians have large parrot-like beaks and skulls that are greatly expanded in the rear. Ex. Triceratops

Question 55

a group of quadrupedal dinosaurs with rows of projecting osteoderm plates down their backs and long osteoderm spikes on their tails.

Answer 55

Stegosaurs

Question 56

Osteoderms

Answer 56

are bones that develop within the skin and are a common component of animal armor.

Question 57

Anklyosaurs

Answer 57

The backs and skulls of most ankylosaurs are covered in spikey protective osteoderms. Some anklosaurs also have large osteoderms on the ends of their tails, forming a mace or “tail club”.

Question 58

bones are the most common dinosaur fossils because

Answer 58

bones decay less rapidly than do softer tissues. This makes it difficult to know what a dinosaur’s integument (body covering) was like.

Question 59

Keratin

Answer 59

a tough but flexible material that also composes hair, feathers, fingernails, and the outside of claws, beaks, and horns.

Question 60

melanosomes

Answer 60

pigment cells within a feather

Question 61

In crocodiles and many birds, there is a large muscle called the __. What does it do?

Answer 61

caudofemoralis.The caudofemoralis pulls backwards on the hind leg and is important for powering birds and crocodiles when they walk and run.

Question 62

The femurs of crocodiles and birds have a prominence of bone, called a

Answer 62

trochanter

Question 63

On most theropods, the trochanter is located high on the femur. A high muscle attachment would have

Answer 63

allowed the caudofemoralis to repeatedly retract quickly – a useful adaptation for carnivorous animals that depend on their ability to swing their legs fast when sprinting after prey.

Question 64

On hadrosaurs, the trochanter is located further down on the femur, this would…

Answer 64

have reduced the speed at which the caudofemoralis could have repeatedly retracted but would have granted the muscle better endurance, because each retraction would have pulled with greater leverage – endurance would have been important for an animal that needed to be constantly on the move and grazing from one patch of vegetation to the next.