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Flashcards in Mesozoic and amniotes Deck (16)
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Describe the key features of the Triassic:

-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%


Describe the key features of the Jurassic period:

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


Describe the key features of the cretaceous:

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


What are the terrestrial causes of extinction?

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


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

-Bolides -Transit through Spiral Arms/Gamma Burst


What are the two main cause of the PT extinction?

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


What are the three different types of skull?

-Anapsid -Synapsid -Diapsid


Describe the anapsid skull:

It has no fenestration at all.


Describe the synapsid skull:

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


Describe the diapsid skull:

Has two temporal openings.


What are the four components of an amniotic egg?

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


What are the features that distingush archosauromorpha?

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


What are the features that distinguish crocodilians from other archosaurs?

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


What are the characteristics of lepidosauromorpha?

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


What are the characteristics of non-avian reptiles?

-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).


What are the similarities between birds and therapods?

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