None

And this applies to every other species, both flora and fauna, that has ever existed.

The past is gone—surviving only in history books, legends, and superstitions. The present is all we have, and we must learn that every species that once walked the planet had its moment in space and time. Nature, in its quiet resolve, turned them to dust. And we, as human beings, share the same fate.

Instead of dreaming about reviving species from the past, we should focus on protecting the ones that still live among us and preserving their habitats. Earth has endured six mass extinctions, and the dinosaurs belonged to the fifth (according to many science books). We know very little about the life that roamed the planet during the five previous “ends of the world,” yet we are likely the only species whose own existence is actively causing its extinction.