Viviparity is considered to be more evolved because
| 1. | the young ones are left on their own |
| 2. | the young ones are protected by a thick shell |
| 3. | the young ones are protected inside the mother's body and are looked after they are born leading to more chances of survival |
| 4. | the embryo takes a long time to develop |
However, in oviparity, the female lays fertilised/unfertilised eggs covered by a hard calcareous shell in a safe place in the environment. The chances of survival are less as the young ones are left on their own.
