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The Fascinating Truth About Dinosaur Colors

When we think of dinosaurs, many of us visualize them as colossal, scaly creatures roving through ancient landscapes in shades of gray and brown, much like the colors depicted in popular media and films. However, recent scientific breakthroughs have painted a vastly different, more vibrant picture of these prehistoric giants, unveiling a world where dinosaurs might have been as brightly colored as the birds we see today.

Unraveling Dinosaur Colors

For decades, the actual colors of dinosaurs were a mystery. Unlike structures such as bones and teeth, pigments do not readily fossilize. Scientists had to rely mostly on guesswork and comparisons with modern-day reptiles and birds, assuming that dinosaurs' coloration would likely serve similar purposes such as camouflage, mating displays, or temperature regulation.

The turning point came with a series of stunning discoveries involving fossilized melanosomes. Melanosomes are microscopic structures in the feathers and skin that contain melanin, a pigment also found in humans. In the early 2000s, researchers began using electron microscopes to analyze the shapes and arrangements of these melanosomes in exceptionally well-preserved dinosaur fossils.

The Case of the Sinosauropteryx

One of the most striking cases was that of the Sinosauropteryx, a small feathered dinosaur from China. Analysis of its fossil revealed that it sported alternating bands of darker and lighter colors along its tail. The distribution and type of melanosomes suggested that these bands were orange and white. This pattern likely helped in camouflage among the undergrowth, hiding it from predators or sneaking up on its prey.

Beyond Camouflage: A Spectrum of Functions

As more dinosaur species were studied, it became evident that coloration in dinosaurs served multiple functions. The Psittacosaurus, a relative of the Triceratops, showed evidence of countershading—a type of camouflage where the animal’s underside is lighter than its top. This gradation of shade would have helped the dinosaur blend into the dappled light of its forested environment, protecting it from aerial predators.

Other dinosaurs, such as the Anchiornis, displayed a more complex arrangement of colors, with speckles and stripes that could have been used for sexual display or species recognition, much like modern birds. The vibrancy and variety of these patterns suggest that visual communication was likely very important in the lives of these ancient creatures.

Implications of Dinosaur Colors

Understanding the coloration of dinosaurs does more than just satisfy curiosity; it provides insights into the behavior and ecology of these ancient animals. Colors can tell us about the environments they lived in, their social behaviors, and even their physiology. For instance, vibrant colors could suggest that dinosaurs had good vision and that their world was not just a fight for survival, but also a stage for complex social interactions.

Moreover, the link between bird and dinosaur colors supports the idea that birds are modern dinosaurs’ direct descendants. The same pigments and feather structures seen in birds today were already present in some dinosaurs millions of years ago.

The Ever-Changing Image of Dinosaurs

The evidence of colorful dinosaurs challenges our traditional views and enriches our understanding of these fascinating creatures. It serves as a reminder of the dynamic nature of scientific discovery, where new tools and techniques can revolutionize our understanding of the past. The age of dinosaurs, it appears, was a more colorful era than we previously imagined.

This fresh perspective on dinosaur colors not only revives our wonder about these ancient creatures but also highlights the evolutionary connections between them and the living birds, providing a vivid link across the ages. As research continues, we may soon find that the truth about dinosaurs is even more colorful than we ever expected.

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A 110 M years old meal found in the stomach of a Nodosaurus

Scientists were able to discover what the prehistoric animal had eaten, over 110 million years ago, before it died. An important discovery: stomachs and evidence of the dinosaurs' diet are rarely well preserved. Occasionally, seeds and twigs have been found in the bowels of dinosaur remains, but never definitive evidence of real plants.

Not this time. A muddy tomb has in fact covered and preserved the dinosaur so well that what was in his stomach before he died also remained there (or almost there). Details of this dinosaur's diet have been published in the Royal Society Open Science magazine.

The leaf fragments and other plant fossils were preserved down to the cells," said David Greenwood, co-author of the study, biologist at Brandon University and adjunct professor at the University of Saskatchewan. "The nodosaurus, known as Borealopelta markmitchelli, was found in 2011 during extraction operations north of Fort McMurray in Alberta, Canada. After its death, the dinosaur's remains ended up in what was an ancient sea, landing on its back in the muddy seabed and remaining undisturbed until nine years ago.

The dinosaur - a type of ankylosaur - weighed more than a ton, but lived away from plants and preferred ferns, according to what the contents of its stomach "revealed".

The discovery of the stomach contents actually preserved by a dinosaur is extraordinarily rare, and this stomach recovered from the mummified nodosaur by the museum team is by far the best preserved dinosaur stomach ever found to date," said Jim Basinger, co-author and geologist at the University of Saskatchewan, in a statement.

Translated with www.DeepL.com/Translator (free version)

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SpaceX Crew Dragon: A Dinosaur on board heading to the ISS

There is also a stuffed dinosaur aboard the Crew Dragon that took off from Cape Canaveral for the International Space Station. A pet donated by one of the two astronauts' sons to their dad. Bob Behnken, 49, and Doug Hurley, 53, are the two former Marine pilots with the rank of colonel aboard Elon Musk's Space X spacecraft. Close friends, two parallel careers and two astronaut wives were chosen by NASA in the same astronaut class in 2000

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Cannibal Allosaurus? The discovery from some "bitten" fossils

According to some recent studies, cannibalism among dinosaurs may have actually existed. Some of the most fearsome carnivores of the Jurassic may have fed on beings of their own species, according to some fossils found in the USA.

The research, published in the journal PLoS One a few days ago, details a series of fossils discovered in the Mygatt-Moore quarry in Colorado, where an unusually high percentage of bite marks on the bones was recorded.

The quarry in question contains a quantity of late Jurassic fossils dating back about 150 million years. Studying over 2,300 bones, a team of paleontologists found that almost 29% showed bite marks from teropod dinosaurs, such as T-Rex, Spinosauro and Allosaurus.

Analyzing these bite marks, the researchers deduced that at least two large teropods - Allosaurus and Keratosaurus - were feeding on abandoned dinosaur carcasses. The quarry is believed to preserve specimens of an ancient wetland ecosystem, where the carcasses were unlikely to disappear rapidly into the mud. This gave the large predators the opportunity to "clean" the bones from the flesh.

The bites found on the bones of teropods were found in regions that provided low nutritional value - suggesting that they were not trying to hunt each other, but only exploiting the remains. The team also believes they discovered evidence of Allosaurus bite marks on the Allosaurus bones. This would be the first evidence of cannibalism in allosaurus.

Large teropods like the Allosaurus probably weren't particularly demanding, especially if their environments were already short of resources," said Stephanie Drumheller, paleontologist at the University of Tennessee, Knoxville, in a press release. "Scavenging and even cannibalism were definitely possible.

Beware, though: the team points out that there may be other reasons for the bites that don't necessarily involve scavenging or cannibalism. For example, these dinosaurs may have been competing for food and then fighting each other. The bites would then be a simple consequence of a fight.

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Elaphrosaurus Fossil discovered in Australia

Researchers at Swinburne University in Melbourne were able to establish that a fossil found in Australia in 2015 belongs to an elaphrosaurus, an extremely rare dinosaur. The study published in the journal Gondwana Research shows that the find found in 2015 near Cape Otway, south-west of Melbourne, belonged to a rare species between T.Rex and Velociraptor, the Elaphrosaurus.

This dinosaur was two metres tall and had a particularly long neck. It was the first fossil of this specimen discovered in Australia.

Despite the fact that only one vertebra of this ancient teropod was discovered in 2015, researchers were able to determine the species, claiming it to be an important advance in paleontology.

First discovery in Australia

As reported to the Guardian by the lead author of the study, Stephen Poropat of Swinburne University in Melbourne, these animals are "really rare". Previously, traces or fossils of elaphrosaurus had been found in Tanzania, Argentina and China but never in Australia.

The vertebra is five centimetres long and was discovered by a volunteer participant in field research. Initially, the researchers had estimated that it was the vertebra of a pterosaur (an extinct order of flying reptiles that lived throughout the Mesozoic). Now the find belongs to the collection of the Melbourne Museum.

Elaphrosaurus

The Elaphrosaurus was a medium size teropod but extremely light and slender. It could exceed 6 metres in length and had very particular characteristics such as an unusually elongated trunk and very short hind limbs in proportion to this. But the most surprising characteristic is that, apparently, when young, these animals had carnivorous teeth, whilst when adult they formed a herbivorous beak.

The fact of having been discovered also in Australia now adds an enigmatic new aspect to this species - seen that 110 million years ago, when the find was discovered, Australia was much further south than now, that is, inside the Antarctic Polar Circle, it is evident that it was a species capable to adapt to several climatic and environmental conditions. It is also true that the poles were much less cold than now at that time, but it is also true that during the austral winters the temperatures dropped in any case below zero degrees and that the polar night lasted the whole season as now.

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How do we tell the difference between a female and a male dinosaur?

A new study found that we don't have enough evidence to distinguish male from female dinosaurs. In fact, female dinosaurs were thought to be larger than male dinosaurs, according to previous studies. However, since the data taken into account is not enough, the previous idea seems to be quite weak.

Some "modern dinosaurs", such as hummingbirds and birds of prey, have what is known as reverse sexual dimorphism, where the females are bigger than the males. There are several hypotheses as to why all this happens, including the fact that being bigger helps the females to produce more eggs. In other species of birds, however, the males are larger. Sexual dimorphism is quite common throughout the animal kingdom. This may also be true in some species of dinosaurs, such as the Shringasaurus indicus. Due to the small number of fossils examined for this species, however, it is not yet possible to draw adequate conclusions. A theme of researchers has tried to detect the differences in size related to sex in 106 specimens of an endangered crocodile species, the Ganges' gharial (Gavialis gangeticus), known to be larger than females.

In the study, when a cavity called "narial fossa" was not taken into account, the team's analysis was unable to accurately distinguish between the two sexes; a document that supports other studies on the lack of evidence of sexual dimorphism in dinosaurs. "Our study suggests that unless the differences between dinosaurs are really impressive, or there is a clear feature such as the narial fossa, we will have difficulty distinguishing a male and female dinosaur using existing skeletons," says zoologist David Hone, of Queen Mary University in London.

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DinoNews: The Spinosaurus lived in rivers and had a crocodile tail.

The spinosaurus was the largest predator dinosaur of all time. It could reach fifteen meters in length and, therefore, exceed the size of a T-Rex. The new bones described by Dal Sasso and colleagues come from the Kem Kem Desert, and were brought to light during a series of excavations between 2015 and 2019. Paleohistological analysis confirmed that the vertebrae found belong to the same individual, found in 2014. And they are a precious treasure for those who study dinosaurs, something hitherto unknown, explains the researcher to Galileo: "For the first time we are facing an almost complete tail (about 80%, nda). Until now, the spinosaurus caudal vertebrae were almost unknown. These bones, instead, show us very elongated caudal spines, therefore a sail-like structure even on the tail".

From semi-aquatic to aquatic animal

In the previous study of 2014, Dal Sasso and his team had already hypothesized various adaptations to a semi-aquatic life: "No one had ever found a spinosaurus tail, so we imagined it as all other dinosaur tails, i.e. made from a tapered cone that ends in a pointed end. The vertebrae brought to light instead had a neural spine above the vertebral body up to seven to eight times the size of the vertebra itself". Overall, the tail appeared tall and flat, like a ribbon. But that's not all: unique characteristics are also present in the zygapophyses, that is, the "articular arms that touch the previous and next vertebrae and, by fitting together, serve to better direct the forces in the bending of the tail". These structures explain Dal Sasso, at the middle of the tail, have already almost disappeared, and then disappear completely. "This makes the bones of the tail have a very high lateral flexibility, comparable to that of certain fish".

"The skeleton of the spinosaurus had to be associated with a musculature capable of moving the tail in an articulated way, certainly a clue that it was used as a propulsive organ", continues Dal Sasso. To confirm this hypothesis, some researchers in biomechanics at Harvard University were also involved. The American scientists made plastic templates corresponding to the tails of newt, crocodile, spinosaurus and other predatory dinosaurs in order to compare their propulsive efficiency in water. The experiment was conducted using a robotic arm to recreate the wavelike movement of the tails.

And the results of the biomechanical analysis proved Dal Sasso's hypothesis right: "The spinosaurus had a tail with a propulsive efficiency much more similar to that of an aquatic reptile, such as the crocodile, or an aquatic amphibian, such as the newt, rather than that of their other terrestrial relatives. We have also recalculated the density of the various parts of the animal, thinking also to the internal organs, and we have seen that, even if with the very long tail, the centre of mass is placed in front of the pelvis and even of the knees. This means that it could not be biped, because it was unbalanced forward. It would be, therefore, the first quadruped teropod, confirming the fact that outside from the waterA confirmation of the hypothesis that it was swimming in the rivers is also the environment where the bones have been found: they are all deposits of fluvial origin. "North Africa itself, in fact, was an entirely different environment. Where today there is a desert, then there were great rivers and lush plains, full of vegetation", the expert goes on. Who also bets on the nature of the spinosaurus' opportunistic predator. "A tooth of this animal - says Dal Sasso - was found planted in the vertebra of a flying reptile: its neck, fossilized, has preserved the trace of who killed it". Even if the diet of these aquatic dinosaurs must have been rich above all in the enormous fish - the size of a car - that at the time were splashing around in those rivers. But if their meals were in the water, their resting places were dry: probably the spinosaurs didn't sleep in the water, but came ashore to rest, perhaps squatting, not standing upright like certain mammals or upright like whales" would have been very clumsy".

But the first ever discovered spinosaurus tail also tells us what kind of life these animals could have had. They were aquatic, yes, but they lived in freshwater rivers, not salt water. "To go to sea you need to have different physiological adaptations, very precise - comments Dal Sasso - like the salt glands in the skull, which are used to secrete excess salts. Nobody has ever found a complete spinosaurus skull, but it probably didn't have salt glands".