The Origin of Tetrapods and the Transition to Life on Land Flashcards
1
Q
The tetrapod clade can be grouped into a crown group and a stem group.
What does this mean?
A
Crown group tetrapoda:
- contain the last common ancestro of all living tetrapods
Stem group tetrapoda:
- crown group + stem group relatives
2
Q
Name four early tetrapods
A
Stem group tetrapods
- Ichthyostega
- Acanthostega
- Parmastega
Stem group tetrapodamorpha
- Tiktaalik
3
Q
What are pentadactyl limbs?
A
Limbs with five digits
ancestral to crown-group tetrapods
4
Q
What are choanae?
A
Internal nostrils
this allows tetrapods to breath through their nose
5
Q
The first evidence of complete territorialisation of tetrapods appears in the Carboniferous.
What is the significance of this?
A
The origin of amniotes.
