SOUTHERN DISTRICT EDUCATION DEPARTMENT

STATE EDUCATIONAL INSTITUTION

EDUCATION CENTER No. 000

PROJECT WORK ON THE TOPIC:

"PALEONTOLOGICAL MYSTERIES OF THE MOSCOW REGION"

Completed:

student 4 "A" class

Kharitonov Vladimir

Scientific adviser:

Moscow, 2010

1. Introduction page 3

2. Main part. Collect additional types of fossils. p.4

2.1 Research methodology. page 5

3. Conclusion page 7

4. References page 8

1. Introduction.

For several years, while vacationing in the summer in the Ruza region in the west of the Moscow region, I found many fossils. Some of them looked like modern sea shells, others resembled corals, the rest were unknown to me.

Looking carefully at my findings, I became interested in how fossils sea ​​creatures found themselves on land, far from all existing seas. I had an assumption that there once was a warm sea in the place of the Moscow region, since similar organisms live in modern warm seas.

Purpose of the study:

prove that there was a sea in place of Moscow and the Moscow region, determine the time of its existence and climatic conditions.

Object of study: paleontological finds.

Subject of study: fossil remains of plants and animals

Methodology and research methods: work on a geochronological scale, observation, analysis, synthesis, classification, generalization

Hypothesis: in place of Moscow and the Moscow region there was a sea.

2. Main part. Collect additional types of fossils.

In order to answer the question I had to study the found fossils. The science of paleontology studies the fossil remains of plants and animals, reconstructing their appearance from found fragments. biological features and habitat.

To confirm my hypothesis, I needed to identify the fossils found and collect additional types of fossils found in the Moscow region. Since September of this year I have been a member of the circle of the Paleontological Institute of the Russian Academy of Sciences. With the circle, we went to fossil sites in the Ramensky, Domodedovo and Lukhovitsky districts of the Moscow region. I was lucky - from each trip I brought fossils of corals, brachiopods, ammonites, gastropods, sea ​​lilies. Three times my finds were chosen by the head of the circle for the collection of the Paleontological Museum.

2.1. Research methodology

What were the fossils I found, and how long ago did they live? To answer these questions, I used special literature.

The age of fossils in paleontology is determined according to the geochronological scale - the chronicle of the origin and development of life on Earth. According to this scale, the time of the Earth's existence is divided into two main intervals (eons): Phanerozoic and Precambrian (Cryptozoic). Cryptozoic is a time of hidden life, when only soft-bodied organisms existed that left no traces in sedimentary rocks. The Phanerozoic began with the appearance of mollusks and other organisms, the remains of which survive to this day.

The corals I found belong to the Carboniferous, Middle and Early Carboniferous eras. Their age is from 354 to 300 million years. The habitat of corals is warm tropical seas, where the water temperature is not lower than 20 °C.

Brachiopods found in the Domodedovo region also belong to the Middle Carboniferous era. Brachiopods or brachiopods are invertebrate marine animals that live on the bottom. Widely distributed to this day in shallow seas from tropical to polar regions.

Ammonites are cephalopods with spirally twisted shells. The ammonites were named in memory of the Egyptian god Ammon, who was depicted with the head and horns of a ram. The ammonites I found in the Lukhovitsky region belong to the Middle Jurassic era and are between 165 and 170 million years old. It is known that there were giant ammonites that would hardly fit in a modern apartment. Ammonites - relatives of living ones cephalopods, such as squids and nautiluses, which still live in warm seas.

Sea lilies - contrary to their name, are bottom-dwelling animals from the class of echinoderms, resembling a flower in shape. Surprisingly, these are predators! There are now about 700 species of sea lilies known in the world. Sea lilies are most diverse in the shallow waters of tropical seas.

The stems of sea lilies I found date back to the Carboniferous, Middle and Early Carboniferous eras. Their age is from 354 to 300 million years.

In the Ramensky district, not far from the village of Gzhel, I found shells of scallops, oysters, and gastropods (or snails). All of them belong to the Middle-Upper Jurassic period and are about 160 million years old. Such mollusks still live in warm seas.

3. Conclusion.

Thus, marine organisms living in little changing conditions and leading a similar lifestyle for millions of years allow us to confirm the hypothesis about the existence of a warm sea on the territory of the Moscow region in the early and middle Carboniferous eras and in the middle and upper Jurassic eras, that is, 360 -300 and 180-150 million years ago.

Solving paleontological mysteries is a very exciting activity and I am not going to stop. My plans include continuing research into the fossil flora and fauna of the Moscow region.

Literature

1. In the darkness of time: Popular science essay. – M.: Bustard, 2002. – 112 p.

2. Morozov manual on collection and determination fossil fauna Mesozoic of the Moscow region. - M.: Moscow city station of young naturalists. 2003

3. Morozov sponges, coelenterates, mollusks and bryozoans of the Carboniferous Russian platform. Guidelines on the collection and identification of fossil fauna of the Moscow region. - M.: Moscow city station of young naturalists. 2006

5. Amazing paleontology: the history of the earth and life on it / . - M.: ENAS, 20 p.

Mysteries of the "Cambrian period"

Kirill ESKOV

One of the mysteries of paleontology is the “sudden” appearance of most types of animals in the Cambrian period. Where did this riot of life come from? What happened before this? It turns out that the “Cambrian attempt” was not the only one. It was preceded by less successful versions of the “act of creation”, which gave rise to a lush fauna that disappeared without a trace.

In the long line of scientific merits of Charles Darwin, there is one: in “The Origin of Species,” published in 1859, he honestly and clearly formulated a number of questions to which his theory did not provide a satisfactory answer (given the then level of knowledge).

The founder of evolutionary theory considered the “Cambrian mystery” to be one of the most serious questions. It is known that fossil representatives of almost all the main divisions of the animal kingdom appear almost simultaneously in Cambrian deposits. In theory, their appearance should have been preceded by a long period of evolution, but for some reason there are no real traces of this process: there are no fossil remains in the pre-Cambrian (Precambrian) layers. None. Why don't you like "act of creation"?

The largest divisions of the geochronological scale are the zones: phanerozoic (from the Greek “phaneros” - visible, obvious, and “zoe” - life; the earliest period of this zone is by whom Bry) and Cryptozoic ("krypton" - in Greek "hidden"), or Precambrian. The fundamental division of the geochronological scale into the Phanerozoic, the earliest period of which is the Cambrian (beginning 0.54 billion years ago) and the Precambrian (0.54 - 4.5 billion years ago), is based on the presence or absence in the corresponding sedimentary rocks of fossil remains of organisms that had solid skeleton.

For almost a hundred years after the publication of the Origin of Species, there was virtually no increase in clarity on this issue. Overall, the Precambrian truly remained the “Dark Ages” of paleontological history, with virtually no “written sources” from it. All ideas about this period (and this is, after all, seven-eighths of the existence of our planet!) were conjectures, the verification of which seemed impossible.

The situation has changed only in recent decades: a real revolution has taken place in the study of Precambrian fossils, the most interesting results of which (as usual!) remain practically unknown general public. Partially paint over it" White spot" and this is the purpose of this article.

Idyll of the "Ediacaran garden"

In 1947, in Ediacara, South Australia, one of the most remarkable discoveries in the history of paleontology was made. It turned out that at the end of the Precambrian - Vendian period (620-600 million years ago) there was a rich fauna of amazing non-skeletal organisms, it was called Ediacaran. Thus, the period reliable existence on Earth, multicellular animals have lengthened by almost 100 million years. Subsequently, Ediacaran fauna was found in several other areas of the world (Namibia, Newfoundland, White Sea); Moreover, it turned out that these creatures had been found many times before (for example, in Ukraine in 1916), but were mistaken for inorganic remains.

What is remarkable about this fauna? All numerous groups of multicellular organisms that appeared at the beginning of the Cambrian were represented by small organisms (millimeters or the first centimeters); the Ediacaran fauna consisted of large or very large invertebrates up to one and a half meters in size. Among them were both radially symmetrical forms, called “medusoids,” and bilaterally symmetrical ones; Some of them (petalonas) look like modern “sea feather” corals, others (like Dickinsonia and Spriggina) - annelids and arthropods. The first researchers of the Ediacaran fauna considered these forms to be the real ancestors of modern coelenterates and worms and included them in the corresponding types and classes of animals. This point of view still has supporters today (the “Australian school”). However, most researchers believe that the similarity here is purely external, and Ediacaran organisms (they were called Vendobionts) represent something completely special and not connected in any direct way with modern groups of animals.

First of all, vendobionts have a different body plan from the Phanerozoic animals we are used to. In almost all bilaterally symmetrical Vendian organisms, this same symmetry is somewhat broken - in the “segmented” forms, the right and left halves of the “segments” are shifted relative to each other, approximately the same as in a zipper or on a herringbone car tread. This asymmetry was usually attributed to the deformations of bodies during the burial process, until M.A. Fedonkin did not pay attention to the fact that the violations were suspiciously regular and uniform. He proved that vendobionts are characterized by a special structural plan, which mathematicians call grazing reflection symmetry; Among multicellular animals, this type of symmetry is extremely rare.

On the other hand, B. Rannegar established that in Vendobionts an increase in body size during the individual development of the organism is achieved through isometric growth, when all body proportions remain unchanged (as with a simple increase in the image of an object). Meanwhile, all known multicellular organisms, including the most primitive ones, such as coelenterates and worms, have not isometric, but allometric growth with a natural change in body proportions (for example, in a person in the series “embryo-child-adult” the absolute size of the head increases, while the relative decreases).

There are also more specific objections to the classification of Ediacaran organisms as modern animal taxa. Under the pressure of these arguments, supporters of a direct relationship between Ediacaran and Phanerozoic animals “handed in” the Vendobionts one by one (“Yes, it seems that Spriggina is not a real arthropod after all...”), and this continued until A Zey-lacher (by the way, it was he who coined the term “vendobionts”) did not propose a fundamentally different solution to this problem. Having summed up the characteristics of Vendian animals, he also cited a common feature for them: they represent various options wide tape with swellings. This type of organization (Seylacher called it a "quilt") is completely different from all that currently exists. Apparently, such a building plan is a special way to achieve large sizes bodies are precisely non-skeletal forms.

Zeilacher believes that the body shape of Vendobionts (“quilt”) with its very high attitude surface to volume allowed them to absorb oxygen and metabolites from water over the entire surface of the body. Indeed, the largest Ediacaran organisms have neither a mouth nor even a semblance of digestive system. Feeding through the surface of the body (this method of feeding is called “osmotrophic”), these creatures did not need internal organs.

Recently, however, D.V. Grazhdankin and M.B. Burzin suggested that the bodies of Vendobionts were not a thick “quilt” at all, but a thin corrugated membrane - by analogy it can be called an “egg carton”. In fact, it is not the membrane itself that ends up in the burial, but those “sand cakes” that are obtained when its “holes” are filled with agitated sediment. These “egg cartons”, having an ideal volume-to-surface ratio, lay motionless on the bottom, absorbing sea ​​water organic matter dissolved in it.

In addition, many researchers believe that these flat (and apparently transparent) creatures were literally stuffed with symbiotic unicellular algae, which made them practically independent of external food sources. Their modern ecological similarity can be the so-called autotrophic animals (it is estimated that coral polyps get up to 70 percent of their food from symbiont algae).

So, in the shallow waters of the Vendian seas there was an amazing ecosystem of “osmotrophic animals”. Thousands of specimens of various representatives of the Ediacaran fauna are now known, but none of them show damage or bite marks; Apparently, at that time there were no predators, or indeed animals that fed on large pieces of food. Therefore, the Vendian biota is often called the “Ediacaran Garden” by analogy with the Garden of Eden, where no one ate anyone. The situation of the Garden of Eden, as it should be, did not last long: at the end of the Vendian, the Vendobionts completely died out, leaving no direct descendants. The Ediacaran experiment, the first attempt in Earth history to create multicellular animals, ended in failure.

Weren't we also "quilts"?

However, there are other opinions regarding the fate of the Ediacaran fauna. In addition to two opposing positions - the “Australian school” and Zeilacher - there is also a “compromise” one. Its supporters believe that the Ediacaran fauna, in addition to the Vendobionts themselves, unique in their organization and characteristic only of this time (and also, possibly, relics of some pre-Vendian faunas), also contains distant ancestors of some Phanerozoic groups.

In this regard, oddly enough, chordates are remembered - the group that crowns the “tree of life”. Let us recall the symmetry of gliding reflection characteristic of vendobionts (and completely atypical for modern animals): elements of such symmetry are found precisely in the structure of the most primitive of chordates - the lancelet. Moreover, one of the Ediacaran organisms - Jurnemnia - with its sac-like body and two “siphons” is very reminiscent of a close relative of chordates - ascidian; In addition, it turned out that the prints of this organism are highly enriched in vanadium, the same metal that serves as the basis for the respiratory pigment of ascidians. So some researchers do not rule out that you and I (as representatives of chordates) descend directly from the most ancient multicellular organisms on Earth - vendobionts.

This, however, is not yet the most exotic hypothesis regarding the nature and family ties Wendobionts. They were declared to be all sorts of things, even giant sea lichens! For example, A.Yu. Zhuravlev proposed a very ingenious hypothesis regarding the relationship of some Ediacaran organisms with giant (up to 20 centimeters in diameter) deep-sea multinucleated xenophyophore amoebae.

Such discrepancies in hypotheses can make a depressing impression on an outside observer, but in “justification” for scientists studying Precambrian organisms, the following must be said. The problem they solve is perhaps the most difficult in all of paleontology, because the actualistic method of reconstruction (by analogy with modernity) clearly works here at the very limit of its resolving power. Paleontologists are actually in the position of astronauts who are faced with the fauna of an alien planet, with the only clarification that they are forced to deal not with themselves alien creatures, but with the “shadow theater” they created.

“Knowledge is Power”, 2001, No. 6

Having again analyzed data on the structure of the mysterious extinct animal, scientists decided that it cannot

Strange fossils, discovered in the middle of the twentieth century. in the territory American state Illinois, became the beginning of one of the most interesting riddles paleontology. In honor of the finder of the first sample, Fra

Having again analyzed data on the structure of the mysterious extinct animal, scientists decided that it cannot be a fish, as was previously thought. The mystery of the Tullymonster remains open.

Strange fossils discovered back in the mid-20th century. on the territory of the American state of Illinois, became the beginning of one of the most interesting mysteries of paleontology. In honor of Francis Tully, who found the first sample, these creatures were called “tullymonsters”; today there are several hundred of them known. The remains are dated to about 310 million years old - at that time, this territory was located rich in life river delta. However, it is not possible to strictly classify these animals.

The prints of soft-bodied tullymonsters are too vague and uncertain, so paleontologists put forward a variety of versions about their structure and appearance, sometimes attributing them to mollusks or arthropods. In 2016, Victoria McCoy and her co-authors described them as relatives of lampreys: “Tullimonster is a vertebrate,” was the title of a paper they published in Nature. “Tullimonster is an invertebrate,” argues a new article published in the journal Paleontology.

Tullymonster could be anyone / Lauren Sallan

The authors of last year's article, having studied more than a thousand remains of tullymonsters, noted a light stripe running along the middle of the body, like a notochord, a primitive spine. Some other details reminded scientists of gill sacs and teeth, also characteristic of vertebrates - more precisely, jawless fish, relatives of modern hagfish and lampreys.

The authors of the new article dispute these interpretations. Lauren Sallan of the University of Pennsylvania and her colleagues note that the position of the elements that were mistaken for gill sacs shows that they were unlikely to be involved in respiration. The location of the part identified as the liver also does not agree with the structure of the vertebrate. In their work, Sallan and her co-authors looked at the anatomy of the Tullymonster's eyes.

Tullymonster Interpretation: Vertebrate / Nobu Tamura

They already had a rather complex structure and contained melanosomes - cells that accumulate the pigment melanin. However, the shape of the Tullymonster's eyes was still the most primitive, cup-shaped, devoid of a lens. “The problem is that if they have cupped eyes, then they can’t be vertebrates,” says Lauren Sallan, “because all vertebrates have more complex eyes, or have simplified them a second time. Moreover, many other creatures have such eyes - primitive chordates, mollusks and some worms.”

Tullymonsters and analogues of some other structures found in marine vertebrates were not found - traces of the auditory capsule, which serves the animal to maintain balance, and the lateral line, a sensory organ. “One would expect that at least some of the remains would have preserved them,” Sallan emphasizes. “It turns out that these creatures have something that vertebrates shouldn’t have, but they don’t have something that certainly should have existed and been preserved.”

Tullymonster print at the Natural History Museum in Milan / Wikimedia Commons

Thus, the authors again analyze the old data and make the assumption that the Tullymonster still belonged to some group of invertebrates. At the same time, no new research has been carried out, and many experts note that the mystery remains a mystery - the strange creature is also completely unlike a mollusk, a worm, or an arthropod.

New paleontological discoveries are changing established ideas about pterosaurs - and the most bizarre animals that have ever flown above the earth.

Pterosaur and pterodactyl are two names for strange flying creatures; The first of them translated from Greek means “wing-lizard”, the second means “flying finger”.
The remains of such an animal were first found in the 18th century. Since then, scientists have described more than 200 species of winged lizards, but popular ideas about these dragons that reigned in the sky Mesozoic era more than 160 million years, remains the same.
We invariably imagine them as sluggish but very dangerous flying reptiles with long beaks and leathery wings, striding on their hind legs like penguins.

Take, for example, the 1966 film One Million Years B.C., in which Raquel Welch's heroine is carried away by a shrill, squawking purple pterosaur to its nest to feed its young (spoiler alert: the bikini-clad beauty escapes). Has anything changed in 50 years? Not at all: in “The World Jurassic period”, filmed in 2015, pterosaurs still carry more than their own weight in people into the skies. (Just in case, let’s clarify: the last pterosaurs died out 66 million years ago, that is, an entire eternity before people appeared on Earth.)

A huge number of paleontological finds made in Lately, allows us to know that pterosaurs came in a wide variety appearance both size and behavior also varied greatly. Hundreds of species of pterosaurs lived simultaneously, occupying different ecological niches, just like birds today. Among them were giant monsters, such as Quetzalcoatlus ( Quetzalcoatlus northropi), one of the largest flying creatures known today: standing on all fours, it could rival the height of a giraffe, and its wingspan reached 10.5 meters. But there were also sparrow-sized pterosaurs: these sat on branches in ancient forests and, most likely, caught insects.

One of the most interesting finds is fossilized pterosaur eggs. By scanning those that were better preserved, scientists saw embryos under the shell and were able to learn about how they developed. One egg was even found in the oviduct of a female Darwinopterus, which lived in China, and next to it was another, which apparently squeezed out under the weight of the volcanic ash that covered the animal. Mrs. T (as this female was named) became the first pterosaur whose sex was accurately determined. There was no crest on her skull. Perhaps such outgrowths adorned only the heads of males, as they decorate the males of some modern species birds - nature gave them a large, brightly colored crest to attract individuals of the opposite sex.

After all these discoveries, pterosaurs seem to have become closer to us, but scientists still can’t get enough. And on the way to national park Big Bend in southwest Texas, paleontologist Dave Martill of the University of Portsmouth shares with me his working plans: first, meet and admire a rattlesnake; secondly, find a complete Quetzalcoatl skull. The chances of fulfilling the first point of the program are immeasurably higher.

The most important thing for a pterosaur specialist is to be an optimist. Imagining that on such and such a day you will go there and find at least something related to them is like buying a lottery ticket and immediately starting to plan what you will spend the winnings on. Fossils of pterosaurs are extremely rare because their bones were hollow and thin. As for Quetzalcoatlus, we know about it thanks to just a few fragments found in Big Bend Park in the 1970s.

The hollow, ultra-light bones of pterosaurs were good for flight, but are very rarely preserved as intact as these anhanguera remains. In most cases, they are crushed, “as if a roller had passed over them.”

Martill and his colleague Nizar Ibrahim spent three days searching for fossilized bones in the dry riverbeds of the park's lands. They walked up and down the Pterodactyl Ridge (what a promising name!), every now and then checking the maps compiled by the discoverer of this lizard. They delved into all the nuances of geological strata (“Look at these manifestations of the Milankovitch cycles!” exclaimed Martill, meaning that periodic changes in the shape of the Earth’s orbit and the tilt of its axis, as established by the Serbian astronomer Milutin Milankovic at the beginning of the 20th century, affect the climate planet, and this is reflected in the cyclic structure of sedimentary deposits). Having climbed onto a sandstone ridge, from which it seemed impossible to get down, Martill only said: “Where did ours go!”, jumped down and remained safe and sound.

However, the researchers were not able to meet a rattlesnake, nor even find a fragment of a pterosaur bone. As a consolation, they came across the femur of a giant dinosaur, apparently a sauropod. But they are not interested in dinosaurs.

Leaving the national park, paleontologists are developing a plan for a new search for Quetzalcoatlus - they really want to learn more about this amazing lizard, in which everything is unusual: its size, appearance, and behavior - this can be judged by the few fossils remaining from it.

INSTITUTE OF VERTEBRATE PALEONTOLOGY AND PALEOANTHROPOLOGY, BEIJING Some areas of the Zhecholoptera fossil from China show subtle traces of hairs or fluff. (For the first time, such integumentary structures were discovered by Soviet paleontologists in a Jurassic pterosaur.)

Ideas about pterosaurs have changed greatly, even in terms of their appearance and behavior. This is partly explained by the fact that until very recently, scientists had to base their conclusions on an extremely small number of samples.

Pterosaurs had, frankly, a very strange anatomy. It may seem that they were poorly adapted for life on the ground or in the air. Once upon a time they even thought that wing-lizards crawled on their bellies, or imagined them walking on their hind legs with long forelimbs stretched forward, like zombies, and folded wings dragging behind them like a cloak. Later, using fossil traces, it was established that pterosaurs moved on four limbs, but exactly how and where they put their wings was still not clear. And their flying abilities were so doubted that they were considered incapable of getting off the ground except by throwing themselves off a cliff.

“It’s quite common to find individuals whose head and neck were three or even four times longer than the body,” says biophysicist Michael Habib of the Natural History Museum of Los Angeles County. Even scientifically trained artists often make mistakes when depicting them. “They take a bird as a model, but they add webbed wings and a crest to it,” says Michael. “However, the body proportions of pterosaurs were not at all avian.”

Habib decided to reconsider the existing understanding of the biomechanics of pterosaurs using, firstly, a mathematical approach and, secondly, a practical knowledge of vertebrate anatomy, which he acquired from his other work, namely in the laboratory of the University of Southern California Medical School. Like most scientists, Michael believes that the first pterosaurs, which appeared about 230 million years ago, evolved from light, slender reptiles well adapted for running and jumping. The ability to jump—to snatch a flying insect or dodge the teeth of a predator—evolved into the ability to, as Habib puts it, “jump and hover in the air.”

At first, pterosaurs probably only hovered, and then, tens of millions of years before birds (and even more so before bats), became the first vertebrates to master flapping flight.

“You need to jump up on your front legs, like a high jumper on your pole,” explains Habib. To take off from the water, pterosaurs used their wings in the manner of rowing oars: they pushed off the surface. And, again, like oarsmen, they had large, developed shoulders, which were often combined with strikingly small legs - to minimize drag in flight.

The pterosaur's wing was a membrane stretched from the shoulder to the ankle; and it was stretched by its extremely long flying (fourth) finger, which forms the leading edge of the wing. Specimens from Brazil and Germany show that the membrane was riddled with thin muscles and blood vessels. Additional rigidity was given to the septum by the protein strands that “stitched” it. Scientists now believe that pterosaurs could have slightly modified their wing profiles depending on flight conditions, by contracting muscles or turning their ankles inward or outward.

Changing the angle of the ossified tendon at the wrist, the pteroid, may have served the same purpose as flaring the slats on large modern aircraft—increasing lift at low speeds.

In addition, pterosaurs involved more muscles and a larger proportion of body mass in flight than birds. And in their brain, like that of birds (and even better), the frontal and visual lobes, the cerebellum and the labyrinth were developed: such a brain could quickly respond to changes in the situation in flight and transmit signals to numerous muscles that regulated the tension of the membrane.

Thanks to the work of Habib and his colleagues, pterosaurs no longer appear as winged misunderstandings, but as skilled aviators. Many species appear to have been adapted for slow but very long flight over long distances; they could float over the ocean using weak, warm updrafts of air (thermals). There were also species that Habib calls superflyers: for example, the albatross-like Nyctosaurus, whose wingspan reached almost three meters, had gliding qualities, especially the distance it flew for each meter of descent, that were quite comparable to the characteristics of modern sports glider.

“Okay, everything is clear with the wings,” one paleontologist began one day after Habib’s lecture. “But what can you say about the heads?” In Quetzalcoatlus, for example, the skull could be three meters long, while the body was less than a meter. And Nyctosaurus had a long “mast” sticking out of its huge skull, to which a crest was probably attached.

Answering the question, Michael talked about the brain of pterosaurs, the mass of which, like those of birds, only slightly weighed down the huge head, spoke about the bones, which were hollow, also like those of birds, and even lighter. The thickness of the bone walls sometimes did not exceed a millimeter, despite the fact that the bone tissue was formed by numerous crossed layers, which gave strength to the bones (like multilayer plywood). And from the inside, the cavities were crossed with partitions for greater rigidity. All this allowed pterosaurs to achieve large body sizes without a significant increase in mass.

The crested skulls and gaping mouths were so huge that Habib, looking at them, developed the “Hypothesis of the Terrible Gray Wolf": "If you have a big mouth, you can swallow more. And the protruding comb could attract females.” Well, returning to the question of that paleontologist, pterosaurs, according to Michael, were “huge flying killer heads.”

Junchang Lu, one of China's leading paleontologists, greets guests on a busy street in the center of Jinzhou, a major trading city in the northeast of the country, and leads them through a dimly lit corridor of a seemingly ordinary office building. This is actually the Jinzhou Paleontological Museum. Its director opens the door of a small storeroom without windows, and the visitors are exposed to what in any other museum would be the main attraction for visitors: all the shelves and almost the entire floor are occupied by specimens with amazingly complete, in all the smallest details, remains of feathered dinosaurs and ancient birds and, of course, pterosaurs.

On a large, almost shoulder-high stone slab leaning against the wall opposite the door, one can see a large, scary pterosaur with a wingspan of four meters and tiny chicken-like hind legs - Zhenyuanopterus. Its elongated head is turned to the side and seems to consist of only jaws, and the teeth become longer and more closely intersecting each other as it approaches the beginning of the mouth. “This is so that it is convenient to catch fish while floating on the surface of the water,” explains Lu. Zhenyuanopterus is just one of three dozen species of pterosaurs that he has described since 2001 (many are still waiting to be studied, lying on the shelves).

NATIONAL MUSEUM OF NATURE AND SCIENCE, TOKYO The skull of the piscivorous anhanguera was preserved in its natural position - to the delight of paleontologists.

The Jinzhou Museum is one of ten such paleontology museums scattered across Liaoning Province, which is a treasure trove of pterosaur fossils and one of the regions where the discoveries have been made that have put China at the forefront of paleontology in recent times.

In addition, Liaoning is the main arena of rivalry, and people from the outside compare what is happening here, not entirely, however, justifiably, with the “bone wars” that the pioneers of American paleontology, Othniel Charles Marsh and Edward Drinker Cope, waged with each other in the 19th century.

The parties to this rivalry are Lu, representing the Chinese Academy of Geological Sciences, and Shaolin Wang, whose fossil-filled office is located at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing. These pundits, like Marsh and Cope, worked together early in their careers, then went their separate ways, and since then they have treated each other with animosity that is not publicized. “Two tigers cannot live on the same mountain,” their colleague Shunxing Jiang grins.

In the decade and a half that has passed since then, Lu and Wang have more than once surpassed each other in the number of discoveries, and together they described more than 50 new species of pterosaurs - almost a quarter of everything that is known today. However, some of these new species will eventually be recognized as synonyms of the previous ones, as often happens in paleontology. However, the rival parties will have to make even more discoveries in the future. “They would have to work all day long for ten years to describe everything that they have already dug up,” one of the guests notes with envy. Hearing this, Lü raises his eyebrows in surprise: “I think ten years will not be enough.”

The success of Chinese scientists is due not only to competition, but also to the fact that they were in the right place at the right time. China, along with Germany, Brazil, the United States and England, is one of the few countries in the world where 90 percent of all pterosaur fossils have been found. This happened not because pterosaurs lived only in the territories where these countries are now located - fragments of their skeletons are found almost everywhere. It’s just that their remains are more fully preserved here.

This exclusivity is evident in the example of Liaoning Province. At first Cretaceous period, says Lü, in the local forests and small fresh lakes a very diverse community of organisms has developed - dinosaurs, the first birds, many pterosaurs and insects. Due to the fact that volcanoes erupted in the neighborhood from time to time, many animals died under the ash and ended up on the muddy bottom of the lakes. Victims of such disasters found themselves buried very quickly, sometimes even without access to oxygen to the remains; their tissues mineralized faster than they could decompose, and therefore survived. Paleontologists call such localities Lagerstätte (Lagerstätte is German for “deposit”). And yet, such finds still have to be dissected for months - cleared of rock so that all their features can be seen, including, of course, with the help of all kinds of powerful microscopes.

It's only in places like the Beipiao Pterosaur Museum or the recent pterygoid exhibition at the Beijing Natural History Museum that you begin to see fossils differently - as part of a once-great diversity.

For example, Jeholopterus is a pterosaur with a wide frog-like mouth, which scientists suggest hunted dragonflies and other insects. Here is the Ikrandraco, named after the winged creatures from Avatar: it probably flew low above the surface of the water and fished for fish using something like a keel on lower jaw. Here is a dungaripterus (Dsungaripterus) found in Northern China with a thin, upward-curved beak, which it used to pry mollusks and other invertebrates in order to then crush their shells and shells with its tuberculate teeth.

And all this disappeared at the end of the Cretaceous period, 66 million years ago. What was wrong with pterosaurs that eventually went completely extinct? Perhaps the animals they hunted have disappeared? Or in the course of evolution they achieved such gigantic size that they could not survive a global catastrophe, such as an asteroid, while small birds survived?

However, when you look at their perfectly preserved remains in the museum, you don’t think about that - something amazing happens: it seems that these creatures are ready to free themselves from stone captivity and go in search of their missing fragments in order to soar above the earth again.

Click on the magnifying glass in the right corner of the picture to view it in its entirety.

The dramatic increase in biodiversity that occurred during the Cambrian period for a long time was prepared by molecular evolution, which ultimately led to the Cambrian explosion of species diversity.

Trilobite is one of the ancient arthropods, whose appearance occurred in the Cambrian period (photo by mattheaton).

In biology, there is a well-known paradox of the Cambrian explosion. Its essence is that at some point life on earth begins to demonstrate a colossal diversity of forms, traces of which can be found in prehistoric fossils. This moment happened during the Cambrian period - but before then there were no signs of future ones life forms could not be detected. Revolutionary leaps in nature are relatively rare, and if we talk about a planetary scale, they are completely incredible. Meanwhile, one gets the feeling that organisms acquired at once, as if at a massive sale, an incredible number of new characteristics and began to quickly disperse into systematic groups.

Of course, one can assume divine intervention or that some aliens shook out a bag of new species onto Earth. Scientists, however, did not stop trying to find at least some scientific explanation for the paleontological mystery. Charles Darwin pondered the problem of the sudden “emergence” of new fossil species - and came to the conclusion that in such cases archaeologists and paleontologists need to “dig better” in every sense.

A group of evolutionary biologists from several American universities published an article in the journal Science outlining the results of yet another rethinking of the mystery of the Cambrian explosion. Scientists have reconsidered the relationship between the remains of ancient creatures, taking into account the latest finds, as well as the archaeological age of these finds. The genealogical relationships of fossil species with their modern descendants were clarified. In addition, molecular genetics data were used: the researchers reconstructed the genealogy of several genes found in 118 modern species. All together made it possible to clarify the branch points on the family tree and accurately determine when this or that group began its own evolutionary path.

In general, the researchers' conclusions boil down to the fact that the Cambrian Revolution was preceded by a long invisible evolution. Over millions of years, organisms accumulated genetic and biochemical changes that led to the appearance of different forms life: accumulated internal changes finally resulted in external changes. The authors compare this to the Industrial Revolution: inventions, small technological innovations, accumulated over a long period of time without much change in the means of production, until they finally led to a global technological shift.

The accumulated genetic changes were balanced until some time external environment and relationships between species. And from a biochemical point of view different organisms already before the Cambrian they could differ significantly from each other, demonstrating great biodiversity. Subsequently, the slightest environmental shifts should have been enough to allow the accumulated changes to manifest themselves from the outside. By the way, one of the very bold, although rather controversial, hypotheses put forward in the article is the assertion that Precambrian animals ate each other more intensively: this may be one of the reasons for the paucity of Precambrian fossil remains.

This is not to say that the new hypothesis has not attracted the attention of critics. Thus, one of the complaints against the authors is that they did not take into account the so-called orphan genes, which make up approximately 30% of all animal genes. These genes have no homologous siblings, and many believe that their sudden appearance may have been responsible for the Cambrian explosion of biodiversity. However, this hypothesis, alas, contains the word “suddenly,” which science always tries with all its might to get rid of.