Chapter 8 Part 3: Axial Skeleton

Question 1

of cervical vertebrae in amphibians?

Answer 1

single cervical vertebrae; disconnection in pelvic girdle and skull, allows more movement

Question 2

of cervical vertebrae in reptiles?

Answer 2

typically 7 cervical vertebrae

Question 3

of cervical vertebrae in birds?

Answer 3

anywhere from 12-25, heterocoelous centra for lots of movement allowed

Question 4

of cervical vertebrae in mammals?

Answer 4

7 cervical vertebrae

Sloths (5-7) and manatees(8-9) exceptions

Question 5

Describe skeletal structure in turtles

Answer 5

turtles have ball and socket joint model

Question 6

What type of cervical vertebrae typify birds?

Answer 6

Heterocoelous, allows for lots of movement

Question 7

What are the atlas and axis? In which tetrapods are they found?

Answer 7

The atlas has no centrum

Axis (C2): has dent/bump called odontoid process; moved to become part of C2
Axis: has centrum, large portion seen under the dens bump (compare to atlas, atlas does not have this)
Dens up against Back part of atlas, holds up skull (join where doing head nods)

Question 8

What are the parts of a typical amniote rib?

Answer 8

o Tetrapod ribs!
o Tubercolum connection
o Capitulum connection
o Connections have own joint capsules
o Show Costal segment and Sternal segment connections

Question 9

What are uncinate processes? In which vertebrates are they found?

Answer 9

Dents up could be due to the flight muscles along the bone for upstroke and downstroke

Found in birds!

Question 10

A large bony sternum is characteristic of which vertebrates?

Answer 10

birds! aka carina, hold powerful flight muscles

Question 11

Gastralia

Answer 11

• abdominal “ribs” found in lizards, crocodilians, Sphenodon
• Are dermal bone and not true ribs

Question 12

• How many sacral vertebrae are characteristic of amphibians?

Answer 12

1 sacral vertebra

Question 13

How many sacral vertebrae are characteristic of reptiles and most birds?

Answer 13

2 sacral vertebrae

Question 14

How many sacral vertebrae are characteristic of mammals?

Answer 14

3-5 sacral vertebrae

Question 15

Define synsacrum

Answer 15

Fusion of last thoracics, all lumbars, all sacrals, first few caudals

Seen in birds

Question 16

What is a urostyle and in which vertebrates are they found?

Answer 16

o Found in anurans (frogs!)
o Single urostyle, single sacrum connection
o (only have 9 vertebrae)

Question 17

What is a pygostyle? In which vertebrates are they found?

Answer 17

o Fusion of last 4 or 5 caudal vertebrae
o Seen in birds

Question 18

What is a coccyx? In which vertebrates are they found?

Answer 18

Fusion of the last 3 to 5 caudal vertebrae (apes, humans)