The world was completely different 50,000 years ago. It was a time when Neanderthals still walked the Earth, around the same era when they first began to mate with humans. Little lived then that still lives now.

Scientists recently unearthed strange life forms trapped in crystals inside caves located in Naica, Mexico, according to a report from Phys Org. The ancient organisms were estimated to be around 50,000 years old. Even more importantly, they're still alive after dozens of thousands of years underground. In total, 40 different strains of microbes and several viruses were found in the Naica caves that go roughly half a mile deep.

Penelope Boston, head of NASA Astrobiology Institute, presented the team's findings at the American Association for the Advancement of Science conference last Friday, Feb. 17. She explained that the "super life" organisms were able to survive on minerals like iron and manganese.

Read: This Wrinkly Bag-Like Sea Creature Was Humans' Oldest Known Ancestor

These life forms are unlike anything else on Earth right now with their nearest related genetic relatives still about 10 percent different -- the same difference between humans and mushrooms.

While the discovery of these dormant microbes is valuable to learn about the planet's evolutionary processes and microbial life, it could also act as a cautionary measure for space exploration. Boston pointed out that there is the concern that spacecrafts flying and drilling into other worlds could inadvertently bring Earth organisms there instead.

"How do we ensure that life-detection missions are going to detect true Mars life or life from icy worlds rather than our life?" Boston said in a report from National Geographic. "Aspects of my work illustrate the extreme toughness of life on Earth and the restrictions that places on us."

These findings have not yet been published or peer-reviewed. Boston's team is planning further genetic tests in the laboratory and on site.