Lec 12

Question 1

Sarcopterygians shared features

Answer 1

Intracranial joint between anterior and posterior portions of the braincase

Basal members having cosmoid scales

Lobe fin

Question 2

Intracranial joint between anterior and posterior portions of the braincase

Answer 2

Motions at the intracranial joint powered by muscles homologous to our eye muscles

Question 3

Basal members having cosmoid scales

Answer 3

Thin enamel and thick dentine on top of two layers of bone

Found in sarcopterygian fishes

Question 4

Lobe fin

Answer 4

Muscle positioned along the skeletal elements of the fin

Single bone connected to the pectoral girdle

A new series of bone called mesomeres formed a central axis of the fin

Radial bones and fin rays become symmetrical in actinistians and dipnoans

Question 5

Acntinistia (Coelacanths)