Osteichthyes

Question 1

Facts

Answer 1

• largest group of vertebrates - 32,000+ spp
• represent 95% of all fishes
• first fossil at around 400mya

Question 2

Radiation into 2 groups

Answer 2

During Devonian:
1. Actinopterygii - ray finned fish
•have radials with delicate rays coming off, fins are delicate and flexible
•lost basals
2. Sarcopterygii - lobe finned fish
•more of a bony core associated
•more muscles attached

Question 3

Actinopterygii groups

Answer 3

1. Non-teleosts - shark ancestral features of bony-fishes

2. Teleosts (majority)

Question 4

Sarcopterygian groups

Answer 4

3 main groups:

1. Lungfish - 3 genera
2. Coelacanths
3. Tetrapodomorphs - those that gave rise to the tetrapods