This article in New Scientist reviews the status of ten ancient creatures that, in theory, might be resurrected if we regain more of their genetic material and make some other plausible advances. The include one of my favorites, the terrifying short-faced bear Arctodus simus, along with the sabre-toothed cats, Neanderthal man (though scientists doubt anyone will breach the ethical barrier of asking a modern woman to be the surrogate mother), the Tasmanian thylacine, the dodo bird, the woolly rhinocerous, the armored glyptodont, the giant ground sloth, the Irish elk, the giant beaver, and the moa. (The author also throws in the gorilla as an example of how are rare species might be retrieved of we "lose" it.)
COMMENT: We may never realize most of these possibilities, in part because only a few have ideally suited surrogate mothers to "convert" a recovered genome into an animal. The 800-kg short-faced bear was the giant of the Tremarctine bears, for example, and the last living relative, the spectacled bear of South America. has a body mass 90% smaller. Still, if there is one thing science has taught us, it is to remember this line from Wernher von Braun: "I have learned to use the word 'impossible' with the greatest caution."