The structure of vertebrae in the lamprey and chondrichthyans
differ
A How completely they enclose the notochord
b Whether or not they have a neural arch and spine
The pectoral girdles of the dogfish shark and the mudpuppy
differ in that
a The pectoral girdle of the shark is attached to the skull, in
the mudpuppy it is not
b The pectoral girdle of the shark contains a scapular
component, the mudpuppy does not
c The pectoral girdle of the mudpuppy contains a scapula
component the shark does not





