The sail-like fin on the pelycosaur may have served as all but which of the following?
a. sexual display
b. a means of locomotion
c. a means of protection
d. a means of defense
e. a thermoregulatory device
Question 2The feature that distinguishes the two subclasses of bony fish is their:a.
gill structure.
b. skeletal structure.
c. fin structure.
d. teeth structure.
e. scale structure.