Then you have to consider whether you have enough samples to build up a title breeding population. Then you have to consider whether a suitable environment exists, or can be provided, for the cloned species to live in. Why did they go extinct in the first place? Is there still a niche for them? Then, you have to consider that the more intelligent species have actual cultures, behaviours which are learned and passed on rather than being programmed in. You can clone an individual, but if the species had gone completely extinct then you can’t bring back its culture. Again, you need to find a dam who is as close as possible to the original species and who will teach the cloned offspring in a similar way to how natural parents would have done it.