Why don't western people like canned eggs?

Reconstruction of extinct worldsThe blue of the egg

Goldfuß, August (1831): Contributions to the knowledge of various reptiles of the prehistoric world. Nova Acta Physico-Medica Academiae Caesareae Leopoldino-Carolinae Naturae Curiosorum. "I was delighted to a high degree when I received a plate of the lithographic stone in the past autumn," the work says. The Goldfuß Museum at the University of Bonn. Kai Jäger shows me a dinosaur fossil.

"And there is a main plate and a counter-plate of the piece, as we can see here, it is here in such an old box from the 19th century, and when Goldfuß examined it in 1831, he also prepared the piece."

The prehistoric researcher must have received a cream-colored stone slab almost DIN-A-3 in size. In Goldfuß ‘book it goes on to say:

"When they were successfully split up, most of the parts of a skeleton became visible. The natural scientist, who is accustomed to seeing the manifold forms of each class of animals modified only within certain limits, was surprised by the wonderful formation of a prehistoric animal."

Beginning of paleontology

The reddish bones from the upper body of an animal belong to Scaphognatus crassirostris, the "thick beak". A pterosaur. Kai Jäger explains:

"Recently the first dinosaurs had been scientifically described, and so had the first early mammals from the Mesozoic, and that was the very beginning of paleontology."

"The image of this animal always appears, which the unrestrained imagination of a Chinese artist produced. The outlines of the head, the spacious chest, the upright, seated position, and the long wings herald a bird, but where is such a bird found in the living one?" Nature with pointed teeth and claws on the wings? "Asks the researcher Goldfuß in his writings.

"Goldfuß was still very much influenced by romanticism," comments Kai Jäger. It also says:

"If one looks at the lower fracture surface of both plates, one sees several undulating lines on the same, which indicate the superimposition of dense and looser limestone masses, and which were perhaps caused by the enveloped flight membrane of the left arm Flakes of curled and twisted hair straight into the eyes. "

Petrified skin? Hair? How should that be possible? Goldfuß ’colleagues believed that his imagination had run away with him. A fantastic. Or is it a misunderstood genius?

"The problem with Goldfuß was that he was a bit ahead of his time. The next generation of scientists was then very critical and focused on hard facts. And they looked at it and either didn't see these structures at all or said: Well. That's probably something that comes from the rock, because at the time they couldn't imagine that soft tissues could be preserved at all. "

Unimagined research opportunities

"It was questioned at the time Goldfuss lived," reports Hans Sues. It couldn't be what couldn't be. "That is relatively paradoxical. After so many millions of years. Usually, all soft tissues decompose relatively quickly. We are talking about hundreds of thousands, a few million years," admits Jasmina Wiemann.

Anyone who thinks that all of this has changed completely since the middle of the 18th century is mistaken. It is true that completely new techniques have been available to paleontologists for a few years. "And then all of a sudden there are unimagined research opportunities," says Hans Sues.

But the more spectacular the findings, the less inclined colleagues are to recognize them. How sure can we be that life in prehistoric times was actually such that the analyzes and interpretations are correct?

In August Goldfuß’s time in the 1830s, paleontology, the science of the living things in the depths of the earth’s history, was little more than an auxiliary science of geology.

"In the 19th century, fossils were mainly used - especially in Germany - to date rocks. For example in the Rhenish Slate Mountains, the entire layers were classified according to invertebrate fossils and the age was determined."

New discoveries strengthened paleobiologists

Professor Hans Sues is the paleobiology department head at the Smithsonian Institution's National Museum of Natural History in Washington D.C. It was not until the beginning of the 20th century - long after Goldfuß - that the paleobiologists Otto Jaekel and Othenio Abel began to see no longer just strangely shaped stones, but actually the remains of living beings. New discoveries strengthened them.

"First of all there was the discovery of the famous Burgess Shale fauna in British Columbia, Canada, on some animals you can see the digestive tract, on other animals you can see details of the nervous system in connection with the eyes, so that was a great discovery, and then a few decades later you had the famous finds from Messel and the Geiseltal, which are about 47 to 48 million years old, and especially in Messel you have incredible soft tissue preservation; and you always wondered: "How does something like that work?"

A fossil Achäopteryx in the Museum-Solnhofen (imago / imagebroker / Siepmann)

The most important reason lies in the peculiarities of the place of discovery. In Solnhofen, for example, the lime is particularly fine, so that details stand out particularly well.

"In Geiseltal, some cell structures have even been preserved, what happened there: We had lignite, and in the area of ​​lignite, limestone, limestone, limestone from the south, lime-rich water flowed into it, and then it did." practically neutralizes the humic acids, which gives you this fantastic soft tissue preservation. In the Geiseltal, for example, you have roundworms, you have even discovered cells with a nucleus, these were excellent examples. "

However, on closer examination it turned out that it was not the nematode itself that had survived, but only a ghostly shell.

"Afterwards it turns out that the bacteria were fossilized, the bacteria have settled and over time have attracted minerals through their own metabolic activity and have then been mineralized themselves; they are practically lithified over these soft tissues like a patina been - bacteria ghosts. "

New techniques

The shape of the soft tissues has been handed down. The structures themselves had crumbled. Kai Jäger boots up his computer in his office. He shows me a method called "Reflectance Transformation Imaging".

"It is used very often in archeology. Because there are of course a lot of things in archeology, old manuscripts, old pictures, hieroglyphs that are very flat, where you have to tease out minimal differences in relief."

The method is perfect for showing Goldfuss' hair structures.

"We went there and took a lot of photos of this piece. The camera was clamped firmly in the tripod and the object didn't move. But the flash was always moving. That means we took 30 or 40 pictures with different exposure positions."

Kai Jäger loads the Scaphognathus into the program.

"We can also go there and have disruptive elements, for example the color, calculated and change the reflective properties of the surface. And now you can see fine structures much better that were previously very difficult to see with the naked eye."

Now that looks like slate rather. "Exactly, now I've taken out all of the color, now it's black, but what we're seeing here is the surface with a slightly stronger shadow."

August Goldfuß already wrote about this: "The animal was therefore not like the reptiles with scales and shields, but with a fur made of soft, almost one-inch-long hair, perhaps even with feathers in some places."

"If we now zoom in here in the back area a little, then we see that the hair should have been in the centimeter range and was built up like a fluff. I'm already saying hair myself, it's not hair, it's in German no term. In English we call them pycnofibers, "says Kai Jäger.

These are fibers with the same function as fur. Firstly, this shows that August Goldfuß could see better than his successors. And secondly:

"This also allows us to say something about the way of life of these animals, because if an animal needs fur, then that suggests that it wanted to maintain its own body temperature, and that is something that we know nowadays with mammals, with birds, but this is not the case for most of the reptiles living today. "

Rehabilitate August Goldfoot

The pterosaur is likely to have been much more active than today's lizards.

"They couldn't lie lazily in the sun and warm up, they had to be active, and what the down is in a bird, the plumage, which is responsible for isolation, has taken over this hairy structure in the pterosaurs."

If it wanted to crawl, it would have the same difficulties as bats, and the length and weight of the head and neck, as well as the relative weakness of the hind extremities, stood in the way of jumping.

"What Goldfuß did at the time was really outstanding. The man was able to prepare well, probably did it all with candlelight. He then considered what he was seeing, gave interpretations in relation to the way of life, interpretations that we also call today correctly, and all that was an outstanding scientific achievement for the time. "

Model of a Tyrannosaurus Rex (picture-alliance / dpa / Stephan Goerlich)

Kai Jäger and his colleagues rehabilitated August Goldfuß. "Or at least: We have now put Goldfuß a bit back in the light of science in order to give him his place, which he actually deserves as a pioneer in early paleontology."

"Goldfuß made a lot of interesting discoveries. Especially with us, that is, with people who do natural history research like our museum, the older works are often extremely valuable, sometimes they give us food for thought that the new literature didn't even have," says also Hans Sues.

Jasmina Weimann thinks: "These soft tissues that Goldfuß described are just prints. And what we see in our fossils are real soft tissues that have been preserved in their original form; we are really talking about cell debris. Things that actually happen within a few weeks would rot. That's a big difference. "

"And we have to compare these remnants of former living beings with modern living beings if we want to say something about the diet of animals, their ecology in general, both their speciation and their extinction, and that was the beginning of what is known as paleo-biology," explains Hans Sue. Jasmina Weimann adds:

"The conservation research area has been booming since the late 1980s. Then came the first great discoveries in which scientists described the preservation of cell debris, the preservation of blood vessels from dinosaur bones, and since then various laboratories around the world have been involved and tried to find out how this soft tissue can be preserved. These new methods are definitely a quantum leap. As I said: We now have some data where we first have to think up questions, for which these data then provide the answers. "

Biologist: "This dinosaur smells like a carcass"

Mary Schweitzer wasn't all that interested in paleontology when she finished her biology degree. That was at the end of the 1970s. She didn't even want to write a doctoral thesis at all. "But dinosaurs have always fascinated me. So I took a seminar with Jack Horner." Jack Horner is the one who advised Steven Spielberg on the Jurassic Park films.

"When I was preparing the Tyrannosaurus Rex MOR 555 for him, I noticed two things that I initially didn't tell anyone out of fear. First, the internal bone structure of this dinosaur was unchanged. You couldn't tell the difference between the dinosaur and a horse. It was flawless, beautiful. Without any mineralization. Given that we thought they were going to stone, that was impossible. "

The original theory is based on the assumption that the organic, the biological building blocks of the body either decompose or mineralize under high pressure and various chemical processes, that they petrify. The second abnormality was even stranger:

"The bone had a smell. But if it was stone, it shouldn't smell. Smells come from volatile organic compounds. I waited six months before telling Jack, 'You know, that dinosaur smells like a carcass.' And he said, "'Yes, smell bones from Hell Creek. Everyone knows that.'"

Actors Laura Dern, Joseph Mazzelli and Sam Neil help a sick dinosaur. (Photo from 1993). In "Jurassic Park" (UIP)

Hell Creek is a fossil deposit in Mary Schweitzer's home state of Montana in the northwestern United States.

"I thought: If everyone knows, why doesn't anyone care? I think that's the problem: paleontologists who come from geology carry ballast around with them. That's why they don't even notice something like that. Questions like that remain unasked. "

66 million year old blood discovered

Mary Schweitzer wrote her first studies and worked intensively on bones for her doctorate. She looked at the samples under a scanning electron microscope and other methods.

"I saw small, round, red structures in the vascular canals. Nobody had noticed them, at least no one had commented on them. But they were exclusively in the blood vessels and they had cell nuclei like birds - just as dinosaur blood cells should have them."

She also investigated which chemical elements the individual structures consisted of.

"I was able to show that the bones contained no iron at all, but the small, round structures were full of iron. I didn't think anything about it because I didn't expect that they could have survived. It was pure coincidence that we lost the soft tissue Scientific advancement often works like this. I would really like to give myself more credit for it, but it was a coincidence. "

Mary Schweitzer discovered blood that was more than 66 million years old. A sensation. But it happened: nothing. "My dissertation was politely ignored. All of my articles were politely ignored."

Pregnant T-Rex discovered

Mary Schweitzer took over the professorship at North Carolina State University. I meet her there. It is early in the morning. Your green Honda is the only car in the parking lot. In her small, square office, a humidifier hums next to the desk. Next to it a daylight lamp. The room has no windows. As soon as Mary Schweitzer set up her laboratory at Raleigh University in the mid-1990s, she repeated her experiments, using fragments from the interior of dinosaur bones that Jack Horner had just dug up.

"I opened the box and said, 'My goodness, it's a female and she's pregnant!" "My technician had exactly the same expression on her face. Like, 'Now she's crazy.' But like birds, dinosaurs could form medullary bones, a truly unique bone tissue. The estrogen during ovulation triggers its formation. The medullary bones then become whole again absorbed as soon as the last egg is laid. "

A calcium reserve inside the long bones. The dinosaur body has to assemble and disassemble them quickly. This is why the medullary bone contains many blood vessels.

"But I couldn't just stand up and say, 'Look, a pregnant T-Rex.' I needed data. One way of examining medullary bones is to etch them a little."

In fresh bones, the calcium disappears and the proteins of the connective tissue, the collagen, remain. Fossilized dinosaur bones were unlikely to have connective tissue. The acid should only clean the bone a bit to better understand its structure.

"But the reaction was faster than expected. When my technician pulled the fragment out of the acid, it was like rubber. I was shocked. I wasn't expecting it. The doctrine was: 'Nothing organic can survive in dinosaur bones. They're closed old. These things don't last that long. 'That was never checked. "

Mary Schweitzer had exposed connective tissue. That was definitely more spectacular than the evidence of a pregnant female dinosaur.

Color pigments in dinosaur eggs

"The next question was: Is the conserved connective tissue a specialty of these medullary bones? What happens to the organic part of vertebrae? We found blood vessels. And bone cells. That too was actually impossible."

But what else should these structures have been? Mary Schweitzer and her staff went through the options.

"We excluded plant hair, root hair, fungi, a biofilm, bacteria. And we showed that it reacts like modern blood vessels and like modern bone cells."

The mother animal neatly stacked a good two dozen eggs before it left the nest. The Oviraptor - a two-legged predatory dinosaur - never returned. Not for around 75 million years. The elongated, approximately 15 centimeter long eggs have survived in the north of China and over time have taken on the color of the earth that surrounds them: rust-red, the cracks in the shells are the color of verdigris.

"These are small raptors that are relatively closely related to our modern birds. Our modern birds are the only surviving dinosaurs. Oviraptors are dinosaur ancestors of our birds." Jasmina Wiemann conducts research at Yale University in Newhaven in the US state of Connecticut.

If you compare the bones of an Oviraptor to those of modern birds, the similarities are great. He must have had large chest and shoulder muscles, which can be seen from the attachments for the tendons on the skeleton. On his skull he wore a large crest similar to that of a cassowary. Perhaps it was as colorful as this modern bird related to the ostrich and emu.

The first Oviraptor was found on a clutch at the beginning of the 20th century, which is why Henry Fairfield Osborn, who first described it, suspected that the dinosaur was a nest robber - petrification in flagranti, so to speak. Hence the name: "Egg thief".

Unlike most reptiles, who grabbed their prey and simply swallowed it, oviraptors were able to work with the lower jaw against the upper jaw, thereby chopping up food. Maybe he used it to crack clams and other shellfish. Jasmina Wiemann examined other remains than the bones:

"We looked at a wide variety of dinosaur eggshells and chemically analyzed them to find out whether they originally contained pigments."

She used methods from chemistry, she explains: "Our method is called Raman spectroscopy. This is a special form of laser microscopy." And from materials science. "To do this, we used various imaging methods, again with laser spectroscopy, and then we actually see on our eggshells where the different speckles are located and what shape they have."

Jasmina Wiemann and her colleagues knew that all the colors and patterns on the shells of modern birds consist of just two color molecules - one for red and one for blue. "These are chemically very, very stable molecules. That means: They should actually be able to survive in fossils and not be completely decomposed."

Using fresh red and blue eggshells, she taught a computer what chemical structures to look for, and then applied it to fossilized eggshells.

"We actually found pigments in other dinosaur eggshells. Then when we get to our raptor dinosaurs, we have all kinds of egg colors and all kinds of patterns on our eggshells. For example, we see blue eggs, green eggs, we have brown ones Eggs, we have white eggs with different speckles of color on them, mostly black or dark brown. "

That means: The ancestors of today's birds began to lay colored eggs no later than one hundred to 70 million years ago. "We found that oviraptors had blue eggs with brown flecks on them."

Draw conclusions about the way of life of the animals

This information is far more interesting than it appears at first glance. Because it allows conclusions about the way of life of the oviraptors. It therefore delivers something that the shape of the eggs and their position in the nest cannot reveal.

"In modern birds, different egg colors are directly related to behavior. Blue colors are related to paternal brood care. Basically, we can deduce that in oviraptors it was not the mothers who incubated the eggs as we had imagined for a long time, it were actually the fathers. "

So not an egg thief, but a dinosaur that breeds. The brown speckles also reveal something new about the oviraptors:

"It seems as if there was an evolutionary need for parents to be able to identify their own eggs based on the pattern of the eggs, and yes that teaches us more about the entire nest ecology." - "Does that mean there were such things as cuckoo raptors ?", I ask.

"Yes. That's basically how we could imagine it. If we then basically imagine a bird's nest and the host bird is parasitized by cuckoos, then we see that the egg colors of the host bird develop very quickly and change very quickly. And relatively often we see that different egg patterns emerge, which then allow the host bird to identify its own eggs. The cuckoo has to keep up. This is called an evolutionary arms race. "

Such insights are precisely what paleontology makes, says Jasmina Wiemann:

“We use fossils that tell us about life processes in the past to learn more about the future. So basically we can extract information that tells us how these animals grew, how these animals lived, what they feed on that is generally what we can learn on a molecular level. But all of this is still research in our childhood shoes. "

In 2015, Mary Schweitzer, the professor from North Carolina State University, and her colleagues were able to examine a particularly well-preserved specimen of an ichthyosaur from the Hauff Urweltmuseum in Holzmaden near Stuttgart. A dolphin dinosaur, if you will. Like these modern mammals, the ichthyosaur had returned from land to the sea. He breathed with lungs, his skin tinted dark on the top to protect himself against enemies in the air, and his underside light against predators from below.

When the researchers demineralized and examined the skin of this animal, they found something that gave them deeper insight into its way of life:

"We used a variety of methods to detect bubbles. The body quickly loses heat under water. This is not a problem for cold-blooded animals. For warm-blooded animals, it is, because they have to use metabolic energy to keep their body temperature high. The ichthyosaurs are way down on the line of the land creatures, and yet they have an increased metabolic rate after all we could test including the presence of bubbling. "

Blubber is the layer of fat several centimeters thick that whales and seals use to protect themselves against cooling in the sea today.

"It is still elastic! The important thing about the bubbling test was that the fats were made from cholesterol. That means: There are no bacteria behind it, because bacteria and multicellular cells use different fats in their tissues."

Researcher: "Women ask different questions than men"

Mary Schweitzer tested her samples in every way she could think of.

"I think we used around 20 different methods on it. And learned three things - first: Original molecules survived. Second: We can ask these molecules evolutionarily relevant questions. Third: We can use these molecules to to test the evolution of body functions. "

And answer questions about how animals of the Mesozoic reacted to changes in their environment.

"We want to move away from 'you survived' to 'how did you survive?' There is so much to learn there. Dinosaurs, for example, have survived periods of global warming and global cooling, ice houses and heat, they have weathered constant climate change, a lot of CO2, little CO2, a lot of oxygen. And they reacted to this on a molecular level We have 150 million years of data waiting for us to collect it. If we come up with new methods and ask the right questions, I think that is relevant to our world today. "

But the reactions of the specialist colleagues were cautious to say the least. "The more we confirmed our results and made them robust, the more criticism we got," says Schweitzer. I want to know why.

"I can't explain it. Because many studies aren't nearly as thorough as we've tried to be. I have no idea. Maybe because I'm old and from Montana. We lack noble origins. And I think women make other people Asking questions as men, that could also play a role. I don't understand the resistance and the criticism. "

"Goldfuß would have been absolutely thrilled"

"There are many people who doubt that this is actually the original material and not a bacterial biofilm. That is also interesting, but not as sensational as actual blood vessel preservation," explains Hans Sues. "What do you think it takes to prove that it really is so?" I ask him.

"Yes, you have to determine whether the biochemical signal points to a biofilm or whether it is actually the tissue. And she tried to compare that to different birds, emu, ostrich and so on. And so she meant that it was true, but there are just various geo-microbiologists who have questioned that. I'm not an expert, I stay out of it. I follow the literature with great interest. I'm a bone person. "

But the reconstruction of sunken worlds is still making progress.

"We have highly sensitive imaging processes, and if we compare that with Goldfuß‘ drawings, then I could imagine that Goldfuß would have been absolutely thrilled if he had been able to look at his pterosaur membrane with imaging methods from chemistry, "suspects Jasmina Wiemann. "We have so many new discoveries and so many new opportunities. A lot is changing in the research area. It's incredibly exciting."