Amphibian diversity and The Rise of the Amniotes

Question 1

What is the sister group to the Amphibia?

Answer 1

Tetrapodomorpha

Question 2

What are the extant amphibia known as?

Answer 2

Lissamphibia

Question 3

What are the tree ordres of Lissamphibia?

Answer 3

urodela (salamanders)

Anura (frogs and toads)

Caecilians

Question 4

Why is their skin central to the lives of lissamphibia

Answer 4

Their skin is permeable

and thus extensively vasularized for gas exchange

Question 5

What glands are present in the epidermis layer of lissamphibian skin?

Answer 5

• Chromatophores
• Mucus glands
• Poison glands

Question 6

What does the exchange of gas in the lungs and skin of lissamphibians depend on?

Answer 6

Temperatrue

• a low remp more exchange occusre via skin than lungs
• at high temp O2 is exchanged in the lungs but more CO2 is exchanged in the skin

Question 7

What is a spermatophore?

Answer 7

A gelatinous basal attachment with a bag of sperm on top of it produced by male urodela

Question 8

What is an amniotic egg?

Answer 8

An egg that possesses three extra embryonic membranes that are absent from non-amniotes.

These are derived from the embryo but are external to it.

Question 9

What are the part of an amniotic egg?

Answer 9

Amnion
- cushions the embryo in a buffered aqueous environment of the amniotic cavity

Allantois
- A heavily vacularised outgrowth of the gut used to store waste and used in gas exchange

Chorion
Envelopes the egg and co-joins the allantois in late dev to function in gas exchange.
Helps seal off shell.

(also has Albumen and a yolk)

Question 10

How do the Lepidosaura thermoregulate?

Answer 10

Exclusively ectothermic

- thus they regulate behaviourally