What do you all think? Do you think they should be revived? or just let it be, and not try to mess with nature?
I am confused about it…I feel it is ok for some of them to be revived…and not ok for some…like I don’t think the woolly mammoth should be revived 
It is TOOOOOOOOOOOOOO HUGE…and ppl might start killing them all over again!
these are some of the species that could be brought back :
Woolly Mammoth
A museum worker inspects a replica of a woolly mammoth (Mammuthus primigenius), a species that went extinct 3,000 to 10,000 years ago. In March 2012, scientists in Russia and South Korea announced a partnership to try to clone the mammoth and generate a living specimen.
Gastric-Brooding Frog
In this file photo, a tiny froglet can be seen in the mouth of its mother, a gastric-brooding frog. In this novel form of parental care, the female swallowed her fertilized eggs. Her stomach then stopped producing acid, becoming a makeshift womb. Later, she regurgitated fully formed froglets.
Two species of gastric-brooding frogs made their homes in creeks in a relatively small area of tropical forest in Queensland, Australia, the southern gastric-brooding frog (Rheobatrachus silus) and the northern gastric-brooding frog (Rheobatrachus vitellinus). The species were discovered in 1973 and 1984, respectively, but by the mid-1980s they had both disappeared.
Passenger Pigeon
The passenger pigeon (Ectopistes migratorius) numbered in the billions in North America during the 19th century, but by the early 20th century, it had gone extinct, thanks to relentless hunting and habitat pressure. Now, geneticist Ben Novak and a handful of other scientists are working on bringing it back.
Dodo
A dodo skeleton sits opposite a reconstructed model of the extinct bird in the National Museum of Wales, Cardiff. The dodo (Raphus cucullatus) is an extinct flightless bird that once lived on the island of Mauritius in the Indian Ocean.
The last widely accepted sighting of the dodo was in 1662, less than one hundred years after the bird was first described by Dutch sailors. The large birds were preyed upon by sailors and the invasive animals they brought with them. Because Mauritius had few predators, the birds had few defenses.
Pyrenean Ibex
The Pyrenean ibex (Capra pyrenaica) was a wild goat native to the Iberian Peninsula. It went extinct in 2000 due to hunting and competition from domestic animals.
Before the species expired, scientists collected DNA from one of the last living females and froze it, to reduce degradation. Over several years, researchers tried to clone back the species, using a related goat as a surrogate. One of the clones was born in 2009, but it lived for only seven minutes.
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