- The viviparous quadrupeds - literally means four-footed mammals bearing living offspring.
- Females are viviparous and give birth to a single litter of up to five offspring.
- If only these creatures had been able to develop a viviparous capability, so that they could give birth to their babies at sea, they would have an assured future.
- Depending on environmental conditions, it can shift from viviparous to oviparous reproduction, with production of encysted and dehydrated embryos.
- These may be viviparous, in which case the mother's body provides nourishment to the embryo, or ovoviviparous, in which case the eggs develop without additional nourishment inside the mother.