Home Animals Extinct Animals Science Could Bring Back
Animals By Joe Burgett -

Gene editing has come a long way. What we once thought to be science fiction has become reality. Specifically when it involves something known as clustered regularly interspaced short palindromic repeats. The world mostly knows this by its abbreviated name, CRISPR. What exactly is CRISPR? Essentially, it’s a family of DNA sequences that can be found in the genomes of all living creatures, belonging to the prokaryotic organisms. This is an area where you’ll see things like Achaea and even Bacteria. The sequences are formed from DNA fragments of bacteriophages, infected by prokaryotes.

In layman’s terms, CRISPR allows you to edit DNA overall. When put into action at an early enough stage, one could wipe out possible future medical problems. Things like diabetes and other genetic disorders could be eradicated eventually. Once further advancements are made, gene editing could likely be done among adults to help against viruses or potentially things like cancer! However, it’s not only human beings that can benefit. Animals could also, as CRISPR will offer the opportunity to bring back pretty much any extinct species.

The possibilities of CRISPR and future gene-editing material is pretty much endless at this point. Now science will be working to bring back some extinct species and potentially could invent others. We felt it might be good to discuss just some of the species that have been discussed.

Extinct Animals Science Could Bring Back
One brown and a white dodo bird. Photo Credit: Daniel Eskridge/Shutterstock

Dodo Bird

  • Went Extinct: 1662
  • Closest Related Species: Nicobar pigeon

For many years, the Dodo Bird has been mentioned as a species that science wants to bring back. Not many understood why at first, considering it was widely assumed the Dodo was an ignorant bird species. Yet this is kind of a misnomer. The Dodo was used as a kind of dumb animal in Alice’s Adventures in Wonderland, a novel published in the mid-1860s. Some even assumed it was so dumb that it led to its own extinction but this is not really true. The first known mention of the Dodo Bird was in 1598.

Extinct Animals Science Could Bring Back
Dodo bird skeleton. Photo Credit: Sasha Samardzija/Shutterstock

Yet it was said to have last been seen in 1662, less than 100 years after its believed discovery. The bird became a symbol for conservation, and how over-hunting or environmental interference was leading to animal extinctions. There is still so much that we do not know about the species, as it had never truly been studied enough. Through gene editing, we could bring it back from the dead. Its closest living relative is the Nicobar Pigeon, yet the Dodo was actually a flightless bird species, unlike the Nicobar. Yet small alterations like this are easy to make in gene editing.

Extinct Animals Science Could Bring Back
An Irish Elk. Photo Credit: Daniel Eskridge/Shutterstock

Irish Elk

  • Went Extinct: 10,000 years ago
  • Closest Related Species: Fallow Deer & Red Deer

A bit of an issue regarding its name. The Irish Elk was not actually an Elk, but rather, a species of deer. Yes, there is a difference between the two. This was said to be one of the biggest deer species to ever live. Of course, they get their “Irish” name from where we first uncovered fossilized remains, Ireland. Yet they also lived in places like Siberia too. The most recent known version of the Irish Elk was carbon-dated and found to have died sometime around 7,700 years ago in what is now Western Russia.

Extinct Animals Science Could Bring Back
Irish elk. Photo Credit: Wikimedia Commons

Of course, this species is not closely related to any European Elk or North American Moose species. Rather, the closest living relative is the Fallow Deer. They have a lot in common with the Red Deer as well, due to being a larger species of deer. Gene editing could likely bring this species back, but it could become potentially invasive. As a result, if science does bring it back then the Irish Elk may very well only be seen in captivity. Due to the large nature, it could cause problems if re-introduced in the wild.

Extinct Animals Science Could Bring Back
QiQi, a baiji river dolphin that died in 2002, was probably one of the last of his species. Photo Credit: Natural History Museum

Baiji Dolphin

  • Went Extinct: Effectively Extinct In 2002
  • Closest Related Species: Amazon River Dolphin

It is pretty uncommon to see a freshwater dolphin. Most dolphins live in the ocean, made up of saltwater. The Baiji White Dolphin goes by many names, especially to the Chinese. Some call it the Chinese River Dolphin while others have called it the Yangtze River Dolphin. The name does not matter as much as the species itself. We know it to be effectively extinct. This is not confirmed, as people claim to see one here and there. However, the last confirmed sighting was in 2002 with other convincing but not proven reports from 2007 & 2012.

Extinct Animals Science Could Bring Back
Qiqi, the last confirmed baiji dolphin. Photo Credit: Wikipedia

That said, most feel it is gone but if the species is still alive, it is few in number. It’s actually the first known species of dolphin to go extinct in modern times. One can directly tie human interference to this extinction too. China and other nations have poisoned freshwater sources for decades. Not to mention, humans fishing and taking food from the dolphins only lead to many starving to death. This is not even discussing how they were hunted. Gene editing could bring them back, allowing us to learn more about this freshwater species. River Dolphins around the world are few in number, so finding a way to save them is crucial!

Extinct Animals Science Could Bring Back
Hunting Moa Bird. Photo Credit: Wikimedia Commons


  • Went Extinct: 1445
  • Closest Related Species: Tinamous, Emu, Cassowary

The Moa is incredible and when you see one, they might remind you of an Ostrich. While this species is also large and flightless, the Ostrich would be dwarfed by some in the Moa species. There were up to 9 different species of Moa at one point, with most being located in New Zealand. The biggest of the species was up to 12 feet tall while the smallest was about the size of a modern turkey. Belonging to the Ratite group of animals, it is actually the only one known to be completely wingless.

Extinct Animals Science Could Bring Back
An early 20th-century reconstruction of a moa hunt. Photo Credit: Wikipedia

They did not even have vestigial wings that the rest of the Ratite group have. All Moa were herbivores, which is why they weren’t known for attacking humans. They were the largest species of any kind in New Zealand until the Māori people arrived. This Polynesian group would settle in NZ and hunt Moa for food. They were essentially over-hunted into extinction. By around 1445 A.D. the species was wiped out and science feels they could learn a lot from them. Creating this species via gene editing could be quite interesting.

Extinct Animals Science Could Bring Back
California grizzly bear in Natural History Museum. Photo Credit: Wikipedia

California Grizzly Bear

  • Went Extinct: 1924
  • Closest Related Species: Kodiak Bear

The California Grizzly Bear species was said to be one of the most beautiful species of bear ever seen. In fact, the state of California connected heavily with it. The state loved the bear for its beauty, strength, and overall size. It was often looped into the term “Grizzly Bear” with the North American Brown Bear. Yet many found it to be more like the Kodiak Bear, especially due to the size & coloring. When Californians were trying to break away from Mexico in 1846, they actually called themselves the Bear Flag Republic.

Extinct Animals Science Could Bring Back
California grizzly bear in Oakland Zoo. Photo Credit: Dru Kelly/Flickr

When California was added to the United States of America, the Golden Bear was added to its state flag. Several schools use it as a mascot there as well! Sadly, the species went extinct in 1924. The Golden Bear is connected to several legends in the state, with two of the last bears being notable killers of people and other animals. The last killed weighed in around 2,200lbs! Scientists have been discussing bringing this bear back from extinction for decades. Therefore, we expect them to do so with new gene-editing technology. Although, it might take a lot of back-breading and some added characteristics.

Extinct Animals Science Could Bring Back
Specimen of a Japanese wolf at the National Museum of Nature and Science, Tokyo, Japan. Photo Credit: Wikipedia

Japanese Honshū Wolf

  • Went Extinct: 1905
  • Closest Related Species: Gray Wolf

The Japanese Honshū Wolf species might very well be unlike any wolf species you’ve ever seen. It is actually part of the Gray Wolf family but was not as large as modern gray wolves. In fact, they are among the smallest wolves ever known. The reason they are so notable is likely due to Japanese folklore. They were well-regarded as a protector species for humans, similar to how a dog might be today. While the name might have given it away, the species was native to Honshū, Shikoku, and Kyūshū within the Japanese archipelago. If they had a good relationship with the Japanese people, what caused them to go extinct?

Extinct Animals Science Could Bring Back
A stuffed specimen of the Japanese wolf sits on display at the University of Tokyo’s Faculty of Agriculture. Photo Credit: Faculty of Agriculture/The University of Tokyo

The biggest cause was likely rabies. It was introduced to Japan around 1732, and the Honshū Wolf was hit pretty hard by the illness. Due to how rabies affects the brain, it did not take long for the wolf population to infect each other. Naturally, this change in the species caused issues with locals. This, combined with deforestation, led to their ultimate demise by 1905. For a species like this, it makes sense to give them a redo with gene editing. Rabies is a terrible illness that causes us to even put down our family dogs. The Honshū wolf species never even had a chance to combat it. Giving them a fresh start could be good!

Extinct Animals Science Could Bring Back
Quagga in Mokala National Park, South Africa. Photo Credit: Louis Lotter Photography/Shutterstock


  • Went Extinct: 1883
  • Closest Related Species: Namibian Zebra

The Quagga species is incredibly interesting and science is still a bit baffled at how they came to be. This is technically a species of Plains Zebra, but it does not look like a normal Zebra. In fact, while the body is certainly similar, it separates from others due to a smaller pattern of primarily brown and white stripes. Stripes are mostly seen on the front of the body. Yet by the time you get to the mid-section, stripes are less and less visible. The back-end is pretty much all brown and can be compared to a horse. Of course, the distribution and organization of the stripes can differ from Quagga to Quagga.

Extinct Animals Science Could Bring Back
Two quagga standing. Photo Credit: SATRIA NANGISAN/Shutterstock

They often traveled in herds of 30 to 50, a lot like the African Zebra. They were a wild and lively species while also being quite docile. South Africa had the largest known settlement of Quagga but they were hunted heavily by humans. By 1883, the Quagga was officially extinct. Due to the incredibly unique look and attitude of the species, it would be nice to be able to study them more in the scientific community. Gene editing could bring them back, and it could likely result in some absolutely beautiful animals.

Extinct Animals Science Could Bring Back
An illustration of an American Cave Lion. Photo Credit: Pavel Kosintsev/Russian Academy of Science

American Lion

  • Went Extinct: During the Quaternary extinction event
  • Closest Related Species: Modern Lion (Panthera leo) and Tiger (Panthera tigris)

The American Lion or North American Lion, whichever you prefer, is said to be quite impressive. Fossils indicate that it’s at least 25% larger than the modern lion. It’s pretty incredible that the American Lion could get so large. Studies also point to the fact that even male American lions may not have had the flowing mane African lions have. Although, this is debated a lot. However, it’s said that the mane we know of today would not have been part of the American lion’s look, but rather, the males might have a small mane if anything.

Extinct Animals Science Could Bring Back
American Lion. Photo Credit: Dantheman9758/Wikipedia

The species was considered an apex predator for its time (between the Pleistocene to Holocene Epochs). That said, what led to their extinction? It’s widely agreed that they went extinct due to the Quaternary extinction event. This was a period in history when several species died off. When many animals die, even the apex among them will die off too. Yet it is clear that gene editing could bring the American Lion back and some others that went extinct during the Quaternary Event.

Extinct Animals Science Could Bring Back
Great auk bird on a rock. Photo Credit: Ann Stryzhekin/Shutterstock

Great Auk

  • Went Extinct: 1852
  • Closest Related Species: Penguin

As surprising as it might be, the Great Auk species was actually discovered before the Penguin species. They were actually confused for Auks at one point, and even named “Penguins” after the scientific name for the Great Auk, “Pinguinus.” They look similar but their habitat was a bit different. Great Auks naturally thrived in colder environments, mostly in the North Atlantic. They’d show up in Canada, Great Britain, Greenland, Norway, Ireland, and several other places. When the species bred, they’d usually do so in relatively small, isolated islands.

Extinct Animals Science Could Bring Back
Closeup of a great auk in a forest. Photo Credit: Wirestock Creators/Shutterstock

This was an extreme rarity to find due to human interference, so breeding became less common after a while. The species had a terrific relationship with humans for a long time. Sadly, humans began over-hunting the species once friendly toward them. In particular, they were hunted for their skin. Considered useful for human clothing and crafting at the time, Great Auk skin went for a premium. Combined with breeding islands being exposed after the Little Ice Age, the Auk species went extinct. Honestly, it would be a shame not to bring them back via gene editing. They could likely do quite well if given a fresh start in the wild, after building the species in captivity.

Extinct Animals Science Could Bring Back
Atlas Bear. Photo Credit: Wikimedia Commons

Atlas Bear

  • Went Extinct: 1890
  • Closest Related Species: Brown Bear

The extinction of the Atlas Bear is historically saddening, simply due to how it happened. This was one of the most prominent bear species on the planet at one point. In fact, it was one of the few bears that could be seen in North Africa. They also navigated partially into Europe & Asia too. It’s actually the only native African bear species that survived into modern times. The species managed to become a relatively known bear type mostly due to The Romans. They used the species in the Roman Collesium and had them fight Gladiators as well as lions, tigers, and even other bears among others.

Extinct Animals Science Could Bring Back
Atlas bear at Madrid Zoo. Photo Credit: Spencer Wright/Flickr

The Roman Games used these bears for centuries, using upwards of thousands of bears in that time. They made sense for combat because the species was a bit shorter than some other bears. Yet, they still were quite large. Many were around 9 feet in length and weighed over 1,000lbs. However, due to their use in the Roman Empire, the species would drop heavily in numbers. Eventually, due to over-hunting, they went officially extinct in 1890. Due to the unique look of this bear and the fact that it was taken advantage of by humans, a redo using gene editing could be great. They truly deserve it.

Extinct Animals Science Could Bring Back
A flock of passenger pigeons. Photo Credit: Chicago Photographer/Shutterstock

Passenger Pigeon

  • Went Extinct: 1914
  • Closest Related Species: Band-tailed Pigeon

Passenger Pigeons are well known likely due to being one of the biggest examples of man’s interference causing animal extinctions. They were native to North America for hundreds of years and were obviously targeted by Native Americans for food. Yet when Europeans arrived, the hunting ramped up heavily. This led to the species dying down rapidly in the 1800s. At one point, there were reportedly thousands throughout the continent. By the mid-1800s, a slow decline occurred but by 1870, a major decline began.

Extinct Animals Science Could Bring Back
Passenger pigeon portrait. Photo Credit: Samoila Ionut/Shutterstock

The meat was commercialized as cheap food, making more people buy it and demand rising. Thus, we began seeing a massive drop. From 1870 to 1890, just 20 years, the population was completely killed off. Well, all except one in captivity named Martha. She died by 1914 and the population with her. These pigeons were actually good for the environment, fed other animals, and much more. People believe it would be a great species to bring back for multiple reasons, which gene editing could allow us to do.

Extinct Animals Science Could Bring Back
Male Pyrenean ibex in the Sierra de gredos. Photo Credit: Alexandre Boudet/Shutterstock

Pyrenean Ibex

  • Went Extinct: 2000 & 2003
  • Closest Related Species: Iberian Ibex

The Pyrenean Ibex is unique among others on this list. We actually DID bring the species back from extinction, using a form of cloning. The Ibex officially went extinct in 2000, but everyone knew the species was in major decline. This made them realize they needed to get as many skin biopsies and genetic material as they could. The last Ibex, named Celia, was caught in Spain and brought in for numerous rounds of testing. They managed to get some tissue from her ear that they could use, then cryopreserved her after she died in nitrogen.

Extinct Animals Science Could Bring Back
Male Pyrenean Ibex. Photo Credit: Zocchi Roberto/Shutterstock

The team spent 3 years trying to make a successful clone of Celia and finally succeeded in July of 2003. Finally, one was born alive after numerous failures. Sadly, the young Ibex died just a few minutes later due to lung failure. This was the last attempt, yet technology was nowhere near as advanced as it is today. We would not need to clone the creature and gene editing would allow us to create the Pyrenean Ibex without several failures. It would be criminal not to bring the Ibex back after all this.

Extinct Animals Science Could Bring Back
An aurochs cow standing outdoors. Photo Credit: Annabell Gsoedl/Shutterstock


  • Went Extinct: 1627
  • Closest Related Species: European Cattle

The most well-known ancestor of the common domestic cattle today, the Auroch species has multiple connections to other bovines too. The dark coloring in Bulls as well as the horns, the size of water buffalo, and the intelligence of Yaks. The reason we have some of the bovine creatures we do today is due to two major domestication events. These led to evolutionary changes that allowed for some differences to occur, leading to Zebu & Taurine Cattle subspecies.

Extinct Animals Science Could Bring Back
Portrait of an aurochs cow. Photo Credit: Annabell Gsoedl/Shutterstock

It is also interesting to point out that evolution events also led to some surviving in colder environments. Those aurochs became large grazers, leading to so many bovine creatures enjoying grass as their main food source. Even Bison, though similar to buffalo, came to be due to cross-species mating involving the Auroch. That said, it would be tremendous to try and bring the Auroch back using gene editing. Imagine what other species types they could develop with potentially new features that some Auroch did not have. It would be an amazing opportunity!

Extinct Animals Science Could Bring Back
The Tasmanian Tigers. Photo Credit: Razik Maulana Ikram/Shutterstock

Tasmanian Tiger

  • Went Extinct: 1906 (in Australia) the 1930s (in The World)
  • Closest Related Species: Tasmanian Devil

It would be wrong to say that the Tasmanian Tiger was an actual tiger. It actually does not have any relationship to tigers and is actually a marsupial. The species was one of the few carnivorous marsupials and the largest known species type on the planet before it went extinct. They were even once called the Tazmanian Wolf due to their several canine features. However, the real name for the species is Thylacine. How did they come to be known as tigers? This is mostly due to the stripes they had on their body, which resemble what one might see on a tiger.

Extinct Animals Science Could Bring Back
Female thylacine and her juvenile also known as Tasmanian Tiger or Tasmanian Wolf. Photo Credit: Wikipedia

They were formidable predators that were considered incredibly dangerous for humans. This led to mass hunting that forced their extinction in Australia in 1906. They lived in Australia and across Tasmania before this but were strictly confined to the island of Tasmania after the Australian extinction. They’d live into the 1930s before going extinct. It was assumed that some were living there until the 1980s, which is why they were thought to be “critically endangered.” They were upgraded to officially extinct by the 1990s. The overall conclusion for many is that this would be a great creature to bring back using gene editing. It is one of the most unique known to mankind. Why not, right?

Extinct Animals Science Could Bring Back
Haast’s eagle attacking Moa. Photo Credit: Wikipedia

Haast’s Eagle

  • Went Extinct: Around The Early 1400s
  • Closest Related Species: Little eagle and Booted Eagle

Haast’s Eagle was officially the largest eagle to ever exist. In fact, one of their most common prey was the Moa we referenced earlier. To be capable of taking down and/or carrying off a large species like this, the eagle would need to be big and strong. It is widely accepted among the Māori people that this was the “Pouakai species.” The Pouakai is a mythological species of monster birds that would kill and eat humans. Of course, the Haast’s Eagle species went extinct after their main food source, the Moa, was hunted to extinction by the Māori people.

Extinct Animals Science Could Bring Back
Haast’s eagle. Photo Credit: Suzi/Flickr

The eagle species did not last long beyond 1400. Haast’s Eagle is also thought to be one of the few true raptors as well. They were deadly creatures that had talons of pretty good length, which they knew how to use well. Yet they also had a smaller set of wings that allowed them to hunt in crowded forests. Their native land of New Zealand was filled with dense forests until humans arrived. That said, many feel that we could bring the species back using gene editing. Then put them right back into the wild in a land with fewer humans. They might do quite well and eventually get to the size they once were.

Extinct Animals Science Could Bring Back
Northern White Rhinos. Photo Credit: Global Guardian/Shutterstock

Western Black Rhino & Northern White Rhino

  • Went Extinct: 2011 & 2018 Respectively
  • Closest Related Species: Other Black/White Rhino

One of the saddest extinctions in modern times has to be both the Western Black Rhino & Northern White Rhino. While the latter is not completely extinct, the last male died in 2018 and thus effectively extinct the species. There have already been animal advocates that have called for gene editing to bring these two back for years now. The interesting situation here is that, if science did decide to bring back specific animals in gene editing, they’d likely start here. That is mostly because we have a lot of genetic content to use for the two, seeing as there are female Northern White Rhino still living.

Extinct Animals Science Could Bring Back
South Western Black Rhinoceros or Hook-lipped Rhinoceros. Photo Credit: Roger de la Harpe/Shutterstock

Plus, there’s plenty of genetic material for the Western Black too. We could more than likely develop these rhinos without as much gene editing as others. Thus, they’re an easier starting point for most. At the same time, we know they were taken to extinction due to poachers. Therefore, they’d more than likely be kept out of places where poaching was at its highest. That is only if they were re-introduced into the wild.

Extinct Animals Science Could Bring Back
A trio of woolly mammoths. Photo Credit: Daniel Eskridge/Shutterstock

Woolly Mammoth

  • Went Extinct: 4,000 years ago
  • Closest Related Species: Asian Elephant

The Woolly Mammoth is an interesting species. It was thought to have gone extinct dating back 10,000 to 15,000 years ago, yet this was proven false. A small amount of the species landed on St. Paul Island and others ended up on Wrangel Island. They lived on St. Paul until around 5,600 years ago and on Wrangel until around 4,000 years ago. This was shocking to find out, as many assumed they died off much earlier. Meaning they lived thousands of years longer than anyone thought. Of course, everyone knows that bringing back the Wooly Mammoth would be tremendous.

Extinct Animals Science Could Bring Back
Woolly mammoth in an ice age landscape. Photo Credit: Dotted Yeti/Shutterstock

They look a lot like modern elephants but, of course, had hair all over. Mammoths lived alongside humans for years, just like Elephants do today. Pretty much everything about the species is similar but they differ slightly. For example, their tusks and molars would be replaced six times during a normal lifespan. Ultimately, gene editing could bring them back and bring the world something truly special.

Extinct Animals Science Could Bring Back
A saber-toothed cat stands atop a boulder. Photo Credit: Daniel Eskridge/Shutterstock

Saber-Toothed Tiger

Saber Tooth Tigers are often confused for being tigers or possibly an ancestor of modern tigers. They’re actually not related to them at all. Although they do have some relation to clouded leopards, this is only partially. It was easy for early anthropologists and scientists to assume the Saber Tooth Tiger had a connection to modern big cats. Looking at them, they had the size of a modern lion, perfectly sharp and long retractable claws, and impressive teeth. The latter of which included two longer versions that went further down and were perfect for kill shots on any prey they’d hunt down.

Extinct Animals Science Could Bring Back
Saber-Toothed Tiger. Photo Credit: Daniel Eskridge/Shutterstock

They lived for millions of years and were a top apex predator during their time. They went extinct during the infamous Quaternary Extinction event. This was a period in which several large animals began to die off. It is widely assumed that this was due to environmental changes. Faunal density and diversity collapsed, causing the extinction of key ecological material. Thus causing many animals to die off. Gene editing could likely bring back the Saber Tooth Tiger, but it might not be as large as it once was in its comeback.

Extinct Animals Science Could Bring Back
Unicorn. Photo Credit: Digital Storm/Shutterstock


  • Went Extinct: ???
  • Closest Related Species: Likely Modern Horses

We know what you’re going to say: unicorns are only fantasy. They were never real, right? Well, technically speaking they have been mentioned in several different historical documents. Many believe, at least at one point in the past, unicorns in some form likely existed. However, most of those same people believe that they did not exist exactly as we think of them. They were rarely described as magical as some assume, and they didn’t have glitter or anything of the sort. They simply looked a lot like modern horses, just with a single bone coming out of their forehead.

Extinct Animals Science Could Bring Back
3D illustration of an enchanting white unicorn. Photo Credit: Oliver Denker/Shutterstock

Of course, most would say that it is hard to buy into them even still. Where were they? Why can we not find them in fossil form? Both are tough to answer, but if unicorns did exist then gene editing could help. However, you may not have to do much to get the look of what most assume unicorns look like. You could merely edit the genes of a modern horse, which could allow them to develop a horn. That can happen right now, but there is no telling if it would be something they’d pass along to their offspring.

Extinct Animals Science Could Bring Back
Dinosaurs in a park by the lake. Photo Credit: AmeliAU/Shutterstock


  • Went Extinct: Around 66 Million Years Ago
  • Closest Related Species: Modern species such as reptiles and birds

While most of us know our history, it seems that some do not learn from it. We’ve all seen how bringing dinosaurs back could be problematic in movies like Jurassic Park. Yet bringing some back would likely be okay to do. You do not want to bring the T-Rex back due to the obviously problematic nature it could cause. However, could you bring back specific herbivore dinosaurs like the Stegosaurus, Triceratops, and Brontosaurus? It’s likely that you could without having to worry as much about the outcome. They’d likely avoid attacking humans unless otherwise threatened.

Extinct Animals Science Could Bring Back
3D rendering of a Tyrannosaurus Rex. Photo Credit: Herschel Hoffmeyer/Shutterstock

Yet people will likely have to understand that they will not be able to get as large as we know them to be. Oxygen levels were high during their time period, allowing most animals to grow incredibly large. Today, the oxygen level is far less. Therefore, they won’t get to nearly the same size. Gene editing could potentially allow them to get there one day, however. The real issue is how to bring them back. Dinosaurs were not reptiles like many think rather, they were closely related to modern-day birds. Therefore, it might take a long time to get to the dinosaurs we know and love – but it could happen!