A study recently published by Russian scientists showed rotifer, a microscopic animal, has come back to life and successfully reproduced after it got frozen for 24,000 years.

USA TODAY reported that Bdelloid rotifers are known for their ability to endure exceptionally low temperatures. As it has been observed, they could survive from six to 10 years in temperatures as low as four degrees Fahrenheit.

Samples of the microscopic animal were taken from frozen soil the scientists extracted from permafrost in northeastern Siberia.

When the samples were taken back to the laboratory, not only did they thaw, but the animals asexually reproduced too, through the use of a process known as "parthenogenesis", or self-impregnation. The rotifers were able to feed as well.

ALSO READ: Deadly Stonefish: Scientists Unlock Mysteries Behind This Toxic Fish's Venom

'Parthenogenesis'

According to National Geographic, the process known as parthenogenesis enables creatures from "honey bees to rattlesnakes" to have what's described as "virgin births".

Such occurrences can shock people caring for the animals. For instance, Leonie, a zebra shark housed with other female sharks at the Reef HQ Aquarium of Australia, stunned her keepers in 2016 when three of her eggs hatched into living pups.

A few years before that, Thelma, a reticulated python at the Louisville Zoo, which reportedly had never seen a male python, laid six eggs that grew into healthy snakes. Then, in 2006, Flora, a Komodo dragon at England's Chester Zoo, achieved the same feat, puzzling its keepers.

There are two processes involved in sexual reproduction -- an egg and a sperm cell. Each cell provides half of the genetic information essential for the creation of a living organism.

However, in parthenogenesis, the body finds a distinctive way of filling in for the genes, typically provided by sperm.

Ovaries produce eggs through a multifaceted process known as meiosis, where the cells are replicating, reorganizing and separating.

These eggs comprise just half of the chromosomes of the mother, with one copy of each chromosome. These are also known as haploid cells, or cells that have two chromosomal copies identified as diploid cells.

Enduring Ice Crystals Formation

It is the best proof to date that multicellular animals could endure tens of thousands of years in cryptobiosis, the state of nearly totally arrested metabolism, said Stats Malavin, one of the researchers at the Soil Cryology Laboratory at the Puschino Scientific Center for Biological Research in Russia.

The study, A living bdelloid rotifer from 24,000-year-old Arctic permafrost, published in Current Biology, found the animals could endure the ice crystals' formation that takes place during slow freezing, suggesting it has some mechanism to shield all body parts from tremendously low temperatures.

The rotifers are just among the many organisms to have stayed alive after being frozen for thousands of years. Nematodes, a type of worm, were revived in 2018 after they were taken from Siberian sediments at least 30,000 years old.

On the other hand, dead mammals such as mammoths have been discovered in permafrost -- even though there is a giant size difference between the rotifers and the mammoths.

Certainly, added the researcher, the more multifaceted the organism, the trickier it is to preserve it alive while frozen. However, for mammals, this cannot be done at present.

Yet, moving from a single-celled organism to one with a gut and brain, although microscopic, is a major step, he added.

The takeaway, Malavin explained, is that a multicellular organism can be frozen and stored for thousands of years and then revived back to like, a "dream of many fiction writers," IFL Science! said in a similar report.

Information about the rotifer that came back to life after being frozen for 24,000 years is shown on News Time's YouTube video below:

RELATED ARTICLE: Discovering Sleep Behavior of Animals: Which are the Best Sleepers, and Which Ones Sleep the Least? 

Check out more news and information on Animals in Science Times.