Mesozoic and amniotes

Question 1

Describe the key features of the Triassic:

Answer 1

-A great radiation of reptiles began -Its end was marked by a mass extinction event due to the impact of a meteorite -O2 levels drop to 15%

Question 2

Describe the key features of the Jurassic period:

Answer 2

-Pangea become fully divided into Laurasia and Gondwana -Dinosaurs become the dominant large vertebrates -High levels of CO2 and O2 drops even more (11%)

Question 3

Describe the key features of the cretaceous:

Answer 3

-Laurasia and Gondwana break apart into smaller continents. -Radiation of flowering plants

Question 4

What are the terrestrial causes of extinction?

Answer 4

-Ecosystem can be really fragile due to their connectivness -Changing in the geology of the habitat -Biochemical properties of the atmosphere

Question 5

What are the possible extra-terrestrial causes of mass extinction?

Answer 5

-Bolides -Transit through Spiral Arms/Gamma Burst

Question 6

What are the two main cause of the PT extinction?

Answer 6

-Eruption of two bigs volcano -Breaking up of Pangea.

Question 7

What are the three different types of skull?

Answer 7

-Anapsid -Synapsid -Diapsid

Question 8

Describe the anapsid skull:

Answer 8

It has no fenestration at all.

Question 9

Describe the synapsid skull:

Answer 9

A single lateral opening, no temporal opening behind the orbit.

Question 10

Describe the diapsid skull:

Answer 10

Has two temporal openings.

Question 11

What are the four components of an amniotic egg?

Answer 11

1) Amnion 2) Allantois 3) Chorion 4) Yolk sac

Question 12

What are the features that distingush archosauromorpha?

Answer 12

-The presence of an antiorbital fenestra (in front of the eye). -4th trochanter on the femur

Question 13

What are the features that distinguish crocodilians from other archosaurs?

Answer 13

-Development of a secondary palate -They have nostrils on the tips of the snout. -They have a septum in their heart.

Question 14

What are the characteristics of lepidosauromorpha?

Answer 14

The skull has a dorsal temporal opening but lacks a lower temporal fenestra.

Question 15

What are the characteristics of non-avian reptiles?

Answer 15

-Waterproof outer layer to protect from the dry environment. -They mute their skin -Developed new kind of kinetic jaws connected by elastic ligament -New sensory systems (thermal sensors).

Question 16

What are the similarities between birds and therapods?

Answer 16

1) They have a S-shaped neck. 2) Hollow, pneumatic bones.