Dinosaurs: How Well Can We Resurrect the Dead?

We are all more than familiar with animatronics or 3D visual effects of dinosaurs as they are envisaged to have looked in life. But how accurate are they? How are these reconstructions created? 

Here we'll explore the work of the artists behind the reconstructions, and investigate if we could, ever, actually bring extinct animals like dinosaurs back from the dead. 

Hold on tight we are about to take a trip through deep time. 

How accurate are reconstructions of dinosaurs?

Put simply, reconstructions of long-extinct organisms, whether 2D or 3D, are a combination of scientific study and a pinch of the artist's imagination. 

The creation of images of long-dead animals and plants is the domain of a special field known as paleoart. While some artistic license is obviously expected, you might be surprised to find out that most are the end product of long deliberation between the artist and experts in the field. 

Just like the scientific fields of paleontology, palaeobiology, and paleobotany that underpin the reconstructions, the ways in which these extinct organisms are depicted have also changed over the years.

But this was not always the case. From the early days of our fascination with the long past, depictions of extinct animals like dinosaurs have evolved radically over time, so to speak. 

Often, older depictions were much more about the imagination of the artist than actual scientific fact. This is not entirely the artist's fault, as the way we think about how animals like dinosaurs carried themselves and looked in life has also changed over time. 

For a long time, dinosaurs were depicted dragging their tails along the ground — much like many modern reptiles. However, we have since come to understand that this is far from the truth of the matter. 

The most notable examples being the famous recreations of dinosaurs at Crystal Palace or the famous works, at least among palaeo-fans, of venerable artists like Neave Parker. While the former was created over 100 years ago, the work of Parker was largely completed in the 1960s, when the knowledge of the gross morphology of dinosaurs was still very limited compared to the modern-day. 

Take Parker's well-known reconstruction of Iguanodon. Depicted with an upright posture, similar to that of a modern kangaroo, we now know this is complete nonsense. In fact, many of the skeletal reconstructions of the time required the tail bones to be physically broken to achieve this feat. It is now known that Iguanodon would have spent most of its time on all fours with its tail elevated and held above the ground. While it could, at times, conceivably stand on its hind legs only, this was not its usual mode of life. 

Far from being enormous lumbering beasts, dinosaurs are now generally depicted as lithe and vibrant creatures full of vim and vigor. Some, depending on their genus, are also more commonly depicted wrapped in feathers.

A stark contrast to old depictions of dull-colored and dim-witted reptiles of only a few decades ago. This is a trend that will only continue as scientists glean ever more information from the fossil record. 

Paleoart is also not for the faint-hearted. It is a very challenging art form that requires knowledge of anatomy, biology, and the ability to render living things and the environment in near photorealism. Professionals also need to depict behavior and ecology too. 

What is the most accurate reconstruction of an extinct animal?

Only a few years ago, one particularly well-preserved fossil from China was so complete that artists were able to produce what was then termed "the most accurate depiction of a dinosaur ever created". 

The creature in question was a specimen of Psittacosaurus (a partially bipedal relative of the more famous Triceratops). Following a study by Dr. Jakob Vinther, of the UK’s University of Bristol, the overall morphology of the specimen could be created with a very high degree of certainty. 

It even had remains of the creature's cloaca preserved. Not only that but large portions of its scaly skin were also preserved, allowing high-tech analysis that identified preserved pigment cells called melanosomes. 

Using this knowledge, paleoartists were then able to put artistic flesh on the bones. They could also go even further and infer its coloration from analysis of the pigment cells. 

But it gets better. Most paleoartists will also consider the animal's habitat and use modern analogies to get a feel for what the creature may have looked like in life. After all, aspects like coloration in modern animals are, often, a consequence of the animal's lifestyle in the wild. 

Take modern gazelles, for example. They often live on the open plains and consequently tend to have dark backs and light bodies. Modern forest-dwelling creatures, like the roe deer, on the other hand, tend to also have a pale belly, but its back will usually have spots or speckles to imitate the dappled light from the forest canopy. 

While not direct analogies to Psittacosaurus, this gives artists an idea of what herbivorous extinct creatures may have looked like, and how they might have blended into the environment. After mapping the melanosomes on the specimen and studying 3D reconstructions of the animal, it appears more plausible that Psittacosaurus' colored patterning is more in line with spending most of its time in a closed light environment — like a forest setting. 

Confidence in the reconstruction comes from the serendipitous agreement of mapped melanocyte patterns and the way direct and diffuse light cast shadows on the body. This revealed that it would stand out less (reinforced with its camouflage) in a forest environment rather than an open space like a plain.

This kind of reconstruction was widely praised in the palaeo- community and is set to become the standard for future reconstructions of animals like dinosaurs. 

“The days when a paleoartist could simply fabricate any color pattern they wanted for a dinosaur are gone,” Bob Nicholls, the paleoartist behind the reconstruction points out. “We have evidence of color patterns in an increasing number of species, and where we don’t there are a great number of trends in nature that need to be considered, not to mention the variety of ways animals create color.”

Is there any scientific proof for depictions of extinct animals? 

As we've touched upon above, most modern depictions are usually the end result of a close study of a fossil and an analysis of its probable environment during life. With regards to the first part, i.e. putting flesh on the bones, this is the realm of a special field of study called palaeobiology.

By studying how components like muscles and tendons attach to bones in modern animals, we can, with some confidence, begin to reconstruct how long-dead animals probably looked in life. At least their overall body form. 

For serious paleoartists, the reconstructions of extinct animals usually begin with scrutinizing a fossil, either in person or via academic papers. Some of the best, like Brian Engh, a California-based paleo-illustrator, tend to favor investigating fossils first-hand and discussing the creature’s key features with the experts researching it.

“We talk about where and when the creature lived; how it got its meals, mates, and shelter; how it avoided becoming a meal—or failed to avoid becoming a meal—and what it was related to,” Engh explained to the National Geographic magazine. “These discussions lead us to look at modern animals, their anatomy and their environments, and we draw specific visual and ecological ideas from these living creatures.”

In fact, the process can be very enlightening for both the artist and experts. By trying to imagine the creature in life, what and how it ate, moved, etc., some blanks can be inferred. Especially when the original specimen is incomplete. 

This obviously comes with a caveat, as any reconstruction is necessarily a direct consequence of how well the fossil is preserved. This is very much a matter of chance, as the preservation of dead animals from the distant past is an incredibly rare event in and of itself. 

Typically today, when an animal or plant dies, its remains are either eaten or rot away completely. In aquatic environments, you can get a bit of a head start, as dead bodies are readily covered in sediment, if not scavenged. But, on land, there is the added complication of erosion, sun exposure, and various other terrestrial environmental processes that drastically reduces the chances of the creature ever being preserved. 

That being said, an experienced paleoartist, and paleontologist, can usually make an educated guess based on more complete or better preserved related species.

However, sometimes we get very lucky. Around the world, there are some very rich fossil-containing rocks called Lagerstätte (literally meaning "storage place" in German). These incredibly rare layers of rock are literal treasure troves for paleontologists and palaeobotanists. It is in such deposits that some of the most complete fossil remains of extinct animals have been discovered, like the famous Archaeopteryx specimen which was complete with feathers. 

Such fossils are a gift from the past, enabling us to better understand the full form and function of many body parts, and the likely ecological niche a long-extinct creature likely filled. 

How can we work out what color extinct animals were? 

General morphology and the presence (or absence) of features like feathers aside, is there any science behind the choice of colors for extinct animals? Dinosaurs, for example, are commonly portrayed in a wide variety of colorations, ranging from dull pastels to vibrant reds and blues, and everything in between. 

But, as a paleoartist, where on Earth do you begin? 

Since dinosaurs can be thought of as a sort of a halfway house between reptiles and birds, examples from the modern world might be a good place to start. Extant (living) reptiles, for example, tend to be a mixture of earthy tones, but birds like chickens and ostriches (thought to be the closest living relatives of some dinosaurs) come in a wide variety of colors and patterns. 

After all, as the famous geologist, Charles Lyell once said, "the present is the key to the past.". 

Any decision made by a paleoartist, while sound logically, is still simply a case of educated guesswork. Are there any scientific tools that can be used to thin down the options a bit? 

As it turns out, there are some recent developments in the palaeobiological analysis of fossils that may help us bring the dead back to life. Long thought to be an impossibility, the new field of "paleocolor," which works out the changes in colors that occur during the fossilization process, is fast becoming a revolutionary force in the world of paleontology. 

To date, only a handful of extinct animals have been given the new treatment (mainly insects, reptiles, and some dinosaurs), but it is only a matter of time before more specimens are examined using the technique. Such studies will not only give us a hint at the color of long-dead animals and plants but also lift the lid (a little) on their behavior in the wild. 

“When we look at the animals and plants we see in the world around us we see striking colors and color patterns,” explains Maria McNamara from the University of Cork.

“Animals use color for camouflage, for avoiding predators, for mating signals, and also for signaling within their social group. So evidence of color in animals has the potential to tell us about this very enigmatic aspect of the biology of ancient organisms,” McNamara added.

One of the most powerful tools of this field uses chemical signatures from well-preserved fossils to try to uncover what color an ancient organism might have been. This technique is not only very interesting but, more importantly, is also non-destructive, leaving the precious fossil unscathed. 

The technique, called high-energy synchrotron x-ray analysis, is able to look for telltale chemical remnants in preserved impressions of soft tissue, like skin, hair, feathers, etc. Specifically, the technique relies on identifying two common pigments, called eumelanin and pheomelanin.

The former can be found in skin, hair, and other tissues in living organisms and gives them a dark appearance (black, brown, or gray). The latter can also be found in tissues, but tends to provide a pink or red hue. 

To complicate the issue, precious little is really known about the chemistry of pigments in living organisms and tissues. However, some work published in 2016 showed that these pigments tend to have very different chemical signatures. 

Eumelanin, for example, typically contains copper, whereas pheomelanin contains sulfur and zinc. The work was conducted by Roy Wogelius, a geochemist at the University of Manchester in the United Kingdom.

Wogelius and his team wondered if their findings could also be used to look for these same metals in old fossil tissues. If so, it would then be reasonable to infer the approximate color of old tissues.

But before they began on their quest, they would need some viable fossils. Ideally with soft tissues and things like hair still visible. 

Almost miraculously, they found some. Discovered in Germany, a pair of exceptionally preserved fossils of a 3 million-year-old mouse, Apodemus atavus, would do very nicely. This animal is a close relative of the modern European wood mouse, which has reddish fur.

Knowing this, it should be possible to discover if the modern mouse's extinct relative had a similar appearance. And that they did. 

Using chemical imaging and spectroscopy to analyze the fossil, Wogelius and his colleagues discovered sulfur and zinc-rich regions of the preserved fur of the fossils, which were very similar to that of the modern mouse. The research team is confident the technique could also be used for much older fossils, perhaps 30-million-years or older. 

While other techniques do exist, they tend to require small samples of the fossil to be destructively tested. They also only let you know the likely color of a particular point on the fossil, not the overall coloration. 

Think of it as taking a small sample of zebra skin. You might be able to identify if the animal was black or white, but would need to be very lucky to get a piece indicating that a zebra is, in fact, both black and white. 

Could we ever bring dinosaurs back from the dead? 

Creating artistic reconstructions of long-dead creatures is all well and good, but we can only ever really know what they looked like if we could get our hands on a complete specimen. While we have been able to discover some incredible specimens of recently-extinct animals, like mammoths and woolly rhinoceros, the chances of finding a complete T-rex is as close as you can get to impossible. 

So, the next best thing might be to try to bring them back to life, Jurassic Park style. Could this actually be possible?

In Michael Crichton's incredibly popular novel (and the film adaptation, of course), dinosaur DNA is extracted from mosquitos encapsulated in amber. The premise seems plausible on the surface, but is there any scientific support for it? 

Let's start with the amber. Amber is a fossilized tree resin that has been hardened through exposure to high temperatures and pressures as the material progressively gets buried over thousands of years. This treatment hardens the resin into a gemstone that is highly prized by our species. 

Some of this amber does indeed include entombed insects from millions of years ago including mosquitoes. So far, so good. 

However, the fossilization process tends to only preserve the insect's exoskeleton or husk, not its soft internal tissues, and especially not any potential DNA-containing blood. But even if we find a piece of amber with a mosquito that miraculously contains some soft tissues, like its last blood meal, it is highly unlikely viable DNA could be recovered anyway. 

That's if any DNA found is actually from an extinct animal and is not modern contamination. But, suppose the blood is genuine, that doesn't mean it will contain DNA. 

DNA, like many other molecules, degrades over time. To date, the best estimate is that DNA has a half-life of around 521 years, give or take. This means that every 1,000 years, or so, 75 % of the genetic information it contains is lost forever. After only a few million years, in most cases, every single base pair of the DNA will be gone. 

But the problems begin even before the fossilization process has begun. Exposure to sunlight or water also accelerates DNA degradation.

Not only that, but the fossilization process, especially high temperatures, will irrevocably damage and deform the DNA over time too. Combined with DNA's inherent half-life, these processes combined pretty much write off the chance of finding enough DNA from millions of years ago to reconstruct an entire dinosaur. 

But, there are other ways to potentially bring the long-dead back to life. 

So far, the oldest DNA recovered has come from extinct animals preserved in permafrost or subfossils (bones or body parts not yet fossilized). 

Some blood residue has been found in fossilized mosquitoes in the past, but these were not found in amber. The fossil, from the Eocene (45 million years ago) was preserved in lake sediments and had a red pigment in its abdomen. After testing the pigment, it was found to be comprised of hemoglobin-derived porphyrins.

In other words, the substance was the digested leftovers of the mosquito's last dinner. Also, it must have come from a vertebrate source, as hemoglobin is only found in that phylum of organisms.

But this substance is neither blood, nor will it likely contain the mosquito's prey DNA. 

So far, no dice. 

However, the plot does thicken a little. Back in 2015, preserved red blood cells were found in a Cretaceous dinosaur fossil bone. After sectioning the preserved cells using an ion beam, no recognizable DNA-like material appears to have been preserved. 

Bummer.

So, with the likelihood of using genuine ancient DNA pretty much out of the question, could we reverse engineer an extinct animal? Perhaps even a dinosaur?

Since every living organism today is the descendant of a long string of ancestors since the beginning of the emergence of life, could we extract ancient DNA to build a full genome of an extinct animal?

In effect, we would be playing evolution in reverse. 

Interestingly this is a possibility. For example, it is not out of the question to take the genome of something like a chicken and engineer its DNA so that it grows teeth and a tail. 

But you would only be expressing some physical traits of the chicken's dinosaur ancestors not all of it. It might look a bit like a little chicken-sized dinosaur, but wouldn't really be. In fact, in 2006, researchers did manage to tweak poultry DNA to grow a chicken with alligator-like teeth.

This kind of practice also throws up a lot of ethical issues too. As Dr. Malcolm famously said in the film Jurassic Park, "Your scientists were so preoccupied with whether or not they could, they didn’t stop to think if they should."

Just because we could potentially reverse engineer a quasi-dinosaur, or another extinct animal, should we? After all, how could such a creature ever hope to survive in the modern world?

What would it eat? Especially if it evolved before modern plants like grass evolved? Such a creature would be doomed to remain in captivity just to survive. 

However, for recently extinct animals, like, say the Dodo, there could be an argument made for resurrection. Plus, we have plenty of potential DNA sources that could make this a possibility. 

Since these organisms were driven extinct by human action, it may be justifiable to give them a second chance at life. 

For now, it seems highly unlikely that we could ever bring long-extinct organisms back from the dead. It is not only technically improbable, even with the latest tools in our genetic engineering arsenal, but is also a very questionable practice ethically. 

However, through the work of paleoartists and special effects artists, we can still make do with the next best thing. Who knows, one day, fully immersive VR and AR games (and other media) may allow us to walk with dinosaurs in any case. 

We'll have to wait and see.