9. Amphibians

Question 1

What fish adaption is not used on land?

Answer 1

Literal line system

Gills

Question 2

The different phases of the transition from water to land.

Answer 2

Phase 1
Wholly aquatic

Phase 2
The body started to adapt to gravity and go away from the lateral line canals and gills. Used some time on land.

Phase 3
Further adaptions for weight and moving on land. So now they were able to walk. Further retention of the lateral line canals and gills.

Phase 4
Two types.

1. type: Now more or less a fully terrestrial animal (relating to earth). Adults largly independt of water.
2. type: Smaller limbs and hips, and furhter rentention of the lateral line system and gills, but adult largly aquatic (crocidels)

Question 3

Why did fish inhabit the earth?

Answer 3

Because of the lack of oxygen, there could be a lack of food.

The land was colonized by insects and other invertebrates before fish. And plants long before. So there was a lot of food.

So this is an opportunity to explode a new better environment.

They properly wouldn´t go that far, because their skeleton wasn´t that good yet.

Question 4

Tiktaalik

Answer 4

Their fins become more leglike.

Their head is flat, like our times crocodiles, because they properly feating in shallow water.

It´s now not a fish and not a reptile or amphibian. An intermediate between lobe-finned fishes and tetrapods.

Question 5

Themnospondyls

Answer 5

A side branch of the tetrapods that no longer exist. Exstinct.

Found all over the world

Crocodile looking tetrapods

Succesfull group in its time.

Question 6

Lissaphibians

Answer 6

Lissamphibians was the first of amphibians and includes the three major groups of modern aphibians.

frogs and toads
salamanders
caecilians (snake looking amphibians)