In all likelihood, 100 years from now mere knowledge of the entire genetic code will suffice to recreate the animal from scratch. You won't even have to store specimens.
Perhaps much sooner than that, at least with worms. This is a simple organism, it does not need 9 months in a womb like we do.
"In all likelihood, 100 years from now mere knowledge of the entire genetic code will suffice to recreate the animal from scratch."
For some animals, maybe. I'm not so sure of those that require a womb.
A living organism born from a womb is not just the result of its genetics, but also of its interaction with its parent while in the womb.
If an animal is extinct, then you won't have an animal of its species to gestate in, so you'd be forced to either use a different animal or an "artificial womb" (if that ever becomes possible). In either case the environment it gestates in will be different from gestation in the real animal of its own species.
It's an open question whether the result of that will really be the same as the extinct animal, even if the genes are the same.
Yes, that is definitely an important questions. We are probably not that far from fuctional artificial wombs (the research into them seems to be slowed down by ethical concerns rather than by outright impossibility), at least for some animals, but they won't be the same as natural wombs, and the effects down the line are ... unclear to say the least.
Having the genetic code without being able to recreate epigenetic conditions is like having source code but no compiler or reference system architecture.
Perhaps much sooner than that, at least with worms. This is a simple organism, it does not need 9 months in a womb like we do.