Exam 1 Chapter 3B

Question 1

Tetrapods

Answer 1

o Lungs for breathing air instead of water
o Tetrapod appendages to walk
o A neck that allowed the head to move somewhat independently of the trunk
o Better vision
o An ear that had not only a balancing function, but also a better sense of hearing
o A nose that became more and more differentiated from the rostrum of fish
o Keratinized skin (not in amphibians)
o Oral glands: secrete fluids into the oral cavity to moisten food to help in swallowing(need to produce fluid to swallow food)
o Lay eggs with shells (not in amphibians)
o A membrane around their fetuses (amniotic sacs) in utero. making them “amniotes”, along with all the reptiles, birds, and mammals) (not in amphibians)

Question 2

What specific trait gave these early tetrapods the name “labrynthodonts”?

Answer 2

• Labrinth: complex system
• Dont: tooth
• Early basal tetrapods (a paraphyletic group)
• Different from modern amphibians in some important ways:

Question 3

How labrynthodonts are differnet from moderm amphibians

Answer 3

o Had little bony scales in their dermal skin layer
o A tail that looked more fish-like than modern amphibians
o A skull that was more similar to the Rhipidistians
o A system of sensory canals in their skulls (like the lateral line system) that led to the neuromast organs, which detected vibrations in the water
o Modern terrestrial amphibians have lost this system, although the aquatic forms still have it

Question 4

Acanthostega

Answer 4

• early amphibian
  o Many tetrapod features but:
  o Retain tail fin
  o Retain internal gills (“fish” branchial arches)
  o Prominent notochord with vertebral arches
  o Polydactyl feet (n=8)

Question 5

Ichthyostega

Answer 5

• early amphibian
  o Similar to Acanthostega, but without gills

Question 6

Lepospondyli

Answer 6

• labrynthodont group
  o Small, salamander-like amphibians
  o Unique spool-shaped complete vertebrae similar to modern amphibians

Question 7

Temnospondyli

Answer 7

• labrynthodont group
  o A diverse ancient order of small to giant tetrapods
  o Scales and armor-like bony plates
  o Centrum of vertebrae divided into a pleurocentrum and intercentrum
  o Intercentrum: large and wedge-shaped
  o Pleurocentrum: relatively small blocks that fit between intercentra

Question 8

Lissamphibia: modern amphibians

Answer 8

• Terrestrial (and aquatic)
• Lungs and skin for respiration (numerous mucus glands in skin)
• Middle ear cavity with columella(stapes)
• Lay eggs – water necessary

Question 9

What are the 3 living groups of amphibians?

Answer 9

o Salienta: frogs and toads
o Urodela: tailed amphibians
o Gymnophiona: Caecillians (legless amphibians

Question 10

What is the significance of the evolution of the amniotic egg?

Answer 10

o allowed for increased exploitation of land

Question 11

What are the components of this type of egg? (amniotic)

Answer 11

o Leathery shell
o Amnion
o Embryo
o Chorion & Allantois: fuse together to form membrane for gas exchange
 Allantois: nitrogenous waste storage/protein(?)
o Yolk sac: food!

Question 12

Which group of labrynthodont amphibians is ancestral to amniotes?

Answer 12

Anthracosauria: reptile like tetrapods

Question 13

3 types of amniote skulls

Answer 13

Anapsid, Synapsid, and Diapsid

Question 14

Anapsid

Answer 14

no opening

Question 15

Synapsid

Answer 15

1 opening (humans)

Question 16

Diapsid

Answer 16

2 openings (crocodiles)

Question 17

Fenestra

Answer 17

opening science type term lol

Question 18

Anapsids

Answer 18

Diadectmorpha, Mesosaurs, Parareptilia

Question 19

Diadectomorpha

Answer 19

o Typically classified as advanced reptiliomorphs (transitional between amphibians and amniotes) positioned close to, but outside the clade Amniota

Question 20

Mesosaurs

Answer 20

o Anapsids: the oldest known reptiles that developed aquatic adaptations
o Terrestrial-like but move back into water

Question 21

Parareptillia

Answer 21

o Clade of basal sauropsids (anapsids), typically considered the sister taxon to Eureptilia (the group that likely contains all living reptiles and birds)

Question 22

Defining features of Eureptillia (diapsids)

Answer 22

o Scales made from keratin in the outer layer of the epidermis
o Few cutaneous glands
o 3 extraembryonic membranes (amnion, chorion, allantois)
o Vertebral column is more differentiated into regions
o Pelvic girdle that is directly articulated with two sacral vertebrae

Question 23

• What are the members of Archosauromorpha?

Answer 23

o Crocodilians
o Saurischian dinosaurs
o Birds
o Ornithischian dinosaurs
o Pterosaurs

Question 24

Understand the 2 pelvis morphologies found in dinosaurs

Answer 24

Saurischian hip
Ornithischian hip

Question 25

Saurischian hip

Answer 25

Ilium on top, Ischium and Pubis bones separated(triangle shape)

Question 26

Ornithischian hip

Answer 26

Ilium on top, Ischium and Pubis bone together, like sword

Question 27

Ornithischia members of group?

Answer 27

o Ceratopsia
o Stegosauria
o Anylosauria
o Ornithopods
o Pachycephalosauria

Question 28

Members of Saurischia?

Answer 28

 Sauropodomorpha, Theropodabh

Question 29

What is the earliest bird?

Answer 29

Archaeopteryx, derived birds from here

Question 30

2 major groups of modern birds

Answer 30

o Paleognathae
o Neognathae

Question 31

Which order makes up over half of modern bird diversity?

Answer 31

Neognathae/Passeriformes