If we do not have DNA for certain extinct animals, could use dna from living animals to re-create a similiar phenotype?
For example, Australia had a lot of large apex predators, but none of them survived long enough until the settlers arrived. Australia is no plagued by large invasive ungulates, some of which are two big or aggressive for dingos to hunt. So in this example: we want to recreate the Megalania: we have no DNA for it. But, we do have Komodos dragons.
We take the genes from saltwater crocodiles that makes them grow large (about the same size as an average Megalania), edit genes that make them able to support their new larger size more efficiently along with moving faster, and boom! We have a 20ft Komodo Dragon designed for long distance travel that can fill that same niche by hunting invasive horses, donkeys, buffalo, pigs and camels.
Or similarly, if we can not find sufficient DNA for a wooly rhino for example, why not take the fur gene of a bison and put into a white rhinoceros?