Jurassic period. Energopedic short information about the Jurassic period of the Jurassic period began

, Conglomerates formed in a variety of conditions.

Unit of the Jurassic system

The Jurassic system is divided into 3 departments and 11 tiers:

system	the Department	tier	Age, mdomy years ago
a piece of chalk	Lower	Berriasky	less
Yura	Upper (Malm)	Titon	152,1-145,0
		Kimmerjsky	157,3-152,1
		Oxford	163,5-157,3
	Average (Dogger)	Kellovian	166,1-163,5
		Batsky	168,3-166,1
		Bayossky	170,3-168,3
		Aalensky	174,1-170,3
	Nizhny (lias)	Tarsky	182,7-174,1
		Plinsbahsky	190,8-182,7
		Sineural	199,3-190,8
		Gettaang	201,3-199,3
Triassic	Upper	Rhetic	more
Division is given in accordance with IGS as of April 2016

Geological events

213-145 million years ago, a single supercontinent Pangea began to decay into separate continental blocks. Shallow sea formed between them.

Climate

The climate in the Jurassic period was wet and warm (and by the end of the period - arid in the field of equator).

Vegetation

In Yura, huge territories were covered with lush vegetation, primarily a variety of forests. They mainly consisted of fern and gone.

Ground animals

One of the fossil creatures that combine the signs of birds and reptiles is archeopteryx, or a leader. His skeleton was first discovered in the so-called lithograph shale in Germany. Nakhodka was made two years after the exit of the labor of Charles Darwin "The origin of species" and became a weighty argument in favor of the theory of evolution - initially, he was considered the transitional form from reptiles to birds (in fact it was a dead-end branch of evolution, not related to real birds directly) . The archeopteryx flew pretty badly (planned from a tree to the tree), and the size was about rawn. Instead of Beak, he had a pair of toothasts, albeit weak jaws. On his wings were free fingers (from modern birds, they were preserved only in gatin chicks).

In the Jurassic period, small, coated warm-blooded animals are inhabited on Earth - mammals. They live next to dinosaurs and are almost invisible on their background. In the Jurassic period there was a division of mammals on single-pass, compound and placental.

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Notes

Literature

• Jordansky N. N. Development of life on earth. - m .: Enlightenment, 1981.
• Karakash N. I. ,. Jurassic system and period // Encyclopedic dictionary of Brockhaus and Efron: at 86 tons. (82 tons and 4 add.). - St. Petersburg. , 1890-1907.
• Koronovsky N.V., Haine V.E., Yasamanov N.A. Historical Geology: Tutorial. - M.: Academy, 2006.
• Ushakov S.A., Yasamanov N.A. Drift of the mainland and climates of the Earth. - M.: Thought, 1984.
• Yasamanov N.A. Ancient climates of land. - L.: Hydrometeoisdat, 1985.
• Yasamanov N.A. Popular Paleogeography. - m .: Thought, 1985.

Links

• - Site about the Jurassic period, a large library of paleontological books and articles.

←	P but l. e. about z. about j.	Mesoza (252.2-66.0 million years ago)			TO but j. n. about z. about j.	→
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SUBSTANCE characterizing the Jurassic period

The trees stood naked and faceless, lazily shevel saved, sampling branches. The continuous, burnt steppe extended behind them, was lost away behind the wall of a dirty, gray fog ... A lot of frowning, drooping human essences walked back and forth, meaninglessly looking for something, not paying any attention to the world around them, which, and True, did not cause the slightest pleasure to look at him ... the entire landscape was caught up and a yoke, flavored despair ...
"Oh, how terrible here ..." Stella whispered. - How many times did not come here - I can't get used to it ... How do these poor things live here?!.
- Well, probably, these "poor things" were too strongly guided if they were here. After all, no one sent here - they just got what they deserved, however? "Still without giving up, I said."
"But now you look ..." Stella whispered mysteriously.
Before us suddenly an overgrown with a gray greenery cave. And from her, squinting, a high, stately man who did not fit into this poorly, church soul ...
- Hello, sad! - Laskovo welcomed Stranger Stella. - So I led my friend! She does not believe that here you can find good people. And I wanted to show you ... You're not against?
- Hello cute ... - a man answered sadly, - Yes, I'm not so good to show me someone. In vain you ...
Oddly enough, but this sad person I really liked the truth at once. From him I had a force and warmth, and it was very pleasant next to him. Anyway, in any case, he did not look like that of those inventiful, killed by the grief, who surrendered to the mercy of the fate of people who were packed with this "floor".
"Tell us our story, a sad man ..." Lightly smiling, asked Stella.
- Yes, there is nothing to tell there, and there is nothing special to proud ... - Stranger shook his head. - And what do you want?
For some reason, I was very sorry for me ... I haven't know anything about him yet, I was already almost confident that this man could not do something really bad. Well, I just could not! .. Stele, smiling, watched my thoughts that she apparently liked her very much ...
"Well, well, I agree - you are right! .." - seeing her satisfied face, finally honestly admitted.
"But you still don't know anything about him, but everything is not so simple with him," smiling slyly, I pretended to say Stella. - Well, please tell her, sad ...
The man smiled sadly, and quietly pronounced:
"I'm here because I killed ... killed many many." But not at will, but for the need it was ...
I immediately frustrated - I killed! .. And I, stupid, believed! .. But for some reason I did not have the slightest feeling of rejection or dislike. I obviously liked a man, and no matter how I tried, I could not do anything about it ...
- Isn't that the same wines - to kill at will or as needed? I asked. - Sometimes people do not have a choice, right? For example: when they have to defend or protect others. I always admired heroes - warriors, knights. In general, I always adored ... Is it possible to compare with them simple killers?
He looked at me for a long time and sadly, and then answered quietly:
- I don't know, honey ... What I am here, says that the wines are the same ... But by how I feel this guilt in my heart, then - no ... I never wished to kill, I'm just defended his land, I was there a hero ... And here it turned out that I just killed ... Is it right? I think no...
- So you were a warrior? - I asked hopefully. - But then, this is a big difference - you defended your home, your family, your children! Yes, and do not look like a killer! ..
- Well, we are not all like those who see others ... Because they see only what they want to see ... or only what we want to show them ... And about the war - I, too, first Just as you thought, I was even proud ... And here it turned out that there was nothing to be proud. Murder - it is murder and is, and it doesn't matter how it has accomplished.
"But this is not right! .." I was indignant. - What then it turns out - the killer maniac gets the same as the hero ?! .. this is simply can't be, this should not be!
I wooled everything from indignation! And the man sadly looked at me with his sad, gray eyes, in which the understanding was read ...
- The hero and the killer in the same way take away life. Only, probably, there are "mitigating circumstances", as a person protecting someone, even if it takes life, then in a bright and righteous reason. But, one way or another, both of them have to pay for it ... and pay very bitter, you believe me ...
- And you can ask you - how long have you lived? - I was embarrassed a little, I asked.
- Oh, a long time ago ... this is the second time I am here ... for some reason, my two of my life was similar - in both I fought for someone ... well, and then I paid ... And always bitterly ... - The stranger is a little bit dead, as if not wanting to talk about it anymore, but then still continued quietly. - There are people who love to fight. I always hated it. But for some reason, the life of the second time returns me to the same circle, as if they were closed on it, not allowing you to get rid ... When I lived, all the peoples were fighting among themselves ... Some seized strangers - other The same lands were protected. The sons overthrew fathers, the brothers killed the brothers ... Everything was. Someone has accomplished unthinkable feats, someone betrayed someone, and someone turned out to be a coward. But none of them even suspected which bitter will be a fee for all those who were deed in that life ...
- Did you have a family there? - To change the topic, I asked. - Were there children?
- Sure! But it was already so long ago .. .. They once became great-grandfathers, then they died ... And some live again. That was a long time ago...
- And are you still here ?! .. - In horror looking around, I whispered.
I could not even imagine that this is how it exists here a lot, for many years, suffering and "paying" your guilt, without any hope of going from this terrifying "floor" before it comes his hour return to physical Earth! .. And there he will again have to start everything first, so that after when his next "physical" life is over, return (maybe here!) With a whole new "luggage", bad or good, depending on how He will live his "next" earthly life ... and get rid of this closed circle (be it good or bad) I could not have any hope, since, having started my earthly life, every person "encourages" herself on this endless, Eternal circular "journey" ... and, depending on his actions, returning to the "floors" can be very pleasant, or - very scary ...

Jurassic geological period, Yura, Jurassic system, Mesozoic average. It began 200-199 million l. n. and ended 144 million liters. n.

For the first time, the sediments of this period were discovered and described in Yura (Mountains in Switzerland and France), hence the name of the period occurred. The deposits of the Jurassic period are very diverse: limestone, crumpled breeds, shale, magmatic rocks, clays, sands, conglomerates that have formed in a variety of conditions. Deposits of that time is quite diverse: limestone, crumpled rocks, shale, magmatic rocks, clays, sands, conglomerates that have formed in a variety of conditions.

Tectonics of the Jurassic period: At the beginning of the Jurassic period, the Unified Supportant Pangea began to decay into separate continental blocks. Shallow sea formed between them. Intensive tectonic movements at the end of the Triassic and at the beginning of the Jurassic periods contributed to the deepening of large bays, gradually separated by Africa and Australia from Gondwana. Deepened the bay between Africa and America. Eurasia formed the depressions: German, Anglo-Paris, West Siberian. The Arctic Sea flooded the northern coast of the laure. It is thanks to this that the climate of the Jurassic period has become more wet. In the Jurassic period, the outlines of continents are beginning to be formed: Africa, Australia, Antarctica, North and South America. And although they are different than now, but they were formed in the Jurassic period.

Climate and vegetation of the Jurassic period

The volcanic activity of the end of the Triassic - the beginning of the Jurassic period caused the transgression of the sea. The continents were divided and the climate in the Jurassic period became more humid than in the Triassic. In the place of the deserts of a triad period, violent vegetation broke into the Jurassic period. Huge territories were covered with lush vegetation. The forests of the Jurassic period were mainly made up of ferns and gone.

The warm and wet climate of the Jurassic period contributed to the brown development of the planet's plant world.

Fernic, coniferous and cicades formed extensive swampy forests. Araucaria, Tui, Tsicadovy grown on the coast. Ferns and chests formed extensive forest arrays. At the beginning of the Jurassic period, about 195 million liters. n. On the entire territory of the northern hemisphere, the vegetation was rather monotonous. Ginkgy and herbaceous ferns prevailed in the northern plant belt. In the Jurassic Ginggov period were distributed very widely. Hinck trees groves grew throughout the belt.

Tsicadovy and tree ferns prevailed in the southern plant belt.

The ferns of the Jurassic period and today are preserved in some corners of wildlife. Horsetails and planes were almost no difference from modern.

animals: Jurassic - dawn of the dinosaur era. It is the violent development of vegetation that contributed to the emergence of many types of vegetation dinosaurs. The growth in the number of roasting dinosaurs gave impetus to an increase in the number of predators. Dinosaurs settled all over land and lived in forests, lakes, swamps. The range of differences between them is so large that the relatives between them are established with great difficulty. The variety of species of dinosaurs in the Jurassic period was great. They could be a quantity with a cat or chicken, and could achieve the size of huge whales.

The Jurassic period is the habitat of many well-known dinosaurs. From the lizardos, this is Allosavr and diplodok. From the birdhettasks it is a stent.

In the Jurassic period in the air, the winged lizards were reigning, Pterosaurs. They appeared in Triassa, but their flourishing accounted for the Jurassic Perosaurian period was represented by two groups of Pterodactyl and Ramforinhi.

In the Jurassic period, the first birds or something among the birds and lizards appear. Creatures that appeared in the Jurassic period and possessing the properties of lizards and modern birds are called archeopterixes. The first birds are archeopterixes, magnitude, with dove. Archeopterixs lived in the forests. Food predominantly insects and seeds.

Bivalve mollusks are displaced with shallow cats Brahiopod. Brachyopodic shells are replaced by oyster. Double mollusks fill all the life niches of the seabed. Many cease to collect food from the soil and move to pumping water with the help of the gills. Other important events took place in the warm and small seas of the Jurassic period.

The Jurassic period spawned a lot of species of Plesiosaurov and ichthyozavrov, rival with high-speed sharks and extremely movable bone fish. And in the naval depths, Leoplevuradon, without stopping, patrolled its territory in search of food.

But one creature could have been rightfully called the owner of the Jurassic Seas. This is a giant lopelyrodone weighing up to 25 tons. Lopelyrodon was the most dangerous predator of the seas of the Jurassic period, and perhaps in the entire history of the planet.

Jurassic geological period, Yura, Jurassic system, Mesozoic average. It began 206 million years ago, 64 million lasted.

For the first time, the deposits of the Jurassic period were described in Yura (Mountains in Switzerland and France), hence the period name occurred. Deposits of that time is quite diverse: limestone, crumpled rocks, shale, magmatic rocks, clays, sands, conglomerates that have formed in a variety of conditions.

190-145 million years ago In the Jurassic period, the single supercontinent Pangea began to decay into separate continental blocks. Shallow sea formed between them.

Climate

The climate in the Jurassic period was wet and warm (and by the end of the period - arid in the field of equator).

In the Jurassic period, huge areas were covered with lush vegetation, primarily a variety of forests. They mainly consisted of fern and gone.

Suganov- The class of gone, prevailed in the green cover of the Earth. Now they meet in some places in the tropics and subtropics. Dinosaurs wandered under the seven of these trees. Externally, the seeds are so similar to low (up to 10-18 m) palm trees that even Karl Linney placed them in its plant system among palm trees.

In the Jurassic period, the grove of ginkgov trees grew throughout the then moderate belt. Ginkgo - leaf falling (which is unusual for gone) trees with a crown, similar to oak, and with small fan-shaped leaves. Only one species is preserved to this day - the ginko two-haired. Conifers were very diverse, similar to modern pines and cypresses, which flourished at that time not only in the tropics, but have already mastered the temperate belt.

Marine Organisms

Compared to TRIAS, the population of the seabed has changed. Bivalve mollusks are displaced with shallow cats Brahiopod. Brachyopodic shells are replaced by oyster. Double mollusks fill all the life niches of the seabed. Many cease to collect food from the soil and move to pumping water with the help of Jabers. There is a new type of reef communities, about the same as it is now. Its base make up six-coral corals that appeared in TRIAS.

Ground animals

One of the fossil creatures of the Jurassic period, combining signs of birds and reptiles, is archeopteryx, or a first place. His skeleton was first discovered in the so-called lithograph shale in Germany. The find was made two years after the exit of the labor of Charles Darwin "The origin of species" and became a weighty argument in favor of the theory of evolution. The archeopteryix flew quite well (planned from a tree to the tree), and the size was about the crow. Instead of Beak, he had a pair of toothasts, albeit weak jaws. On his wings were free fingers (from modern birds, they were preserved only in gatin chicks).

In the Jurassic period, small, coated warm-blooded animals are inhabited on Earth - mammals. They live next to dinosaurs and are almost invisible on their background.

The dinosaurs of the Jurassic ("terrible lizards" from Greek) lived in ancient forests, lakes, swamps. The range of differences between them is so large that the relatives between them are established with great difficulty. They could be a quantity with a cat or chicken, and could achieve the size of huge whales. Some of them moved on four limbs, others ran in their hind legs. The deft hunters and bloodthirsty predators were among them, but there were harmless herbivan animals. The most important feature inherent in all their species is that they were terrestrial animals.

The Jurassic period is the middle of the Mesozoic era. This piece of history is primarily famous for its dinosaurs, he was very good time for all living things. During the Jurassic period, for the first time, reptiles were dominated everywhere: in water, on earth and in the air.
Title this period was received in honor of the mining chain in Europe. The Jurassic period began about 208 million years ago. This period was more revolutionary than Triassic. This revolutionary was concluded with those estates that occurred with earthly crust, because it was during the Jurassic period that Pangay began to disperse. The climate from this time was warmer and more wet. In addition, the water level in the World Ocean began to rise. All this gave great opportunities for animals. Due to the fact that the climate has become more favorable on land began to appear plants. And corals began to appear in shallow water.

The Jurassic period lasted from 213 to 144 million years ago. At the very beginning of the Jurassic period, the climate throughout the land was dry and warm. There were some deserts around. But later they began to impregnate the moisture rain. And the world has become more green, the magnificent vegetation began to flourish.
Fernic, coniferous and cicades formed extensive swampy forests. Araucaria, Tui, Tsicadovy grown on the coast. Ferns and chests formed extensive forest arrays. At the beginning of the Jurassic period, about 195 million L.N. On the entire territory of the northern hemisphere, the vegetation was rather monotonous. But already starting from the middle of the Jurassic period, about 170-165 million ties, two (conditional) vegetable belts were formed: North and South. Ginkgy and herbaceous ferns prevailed in the northern plant belt. In the Jurassic Ginggov period were distributed very widely. Hinck trees groves grew throughout the belt.

Tsicadovy and tree ferns prevailed in the southern plant belt.
The ferns of the Jurassic period and today are preserved in some corners of wildlife. Horsetails and planes were almost no difference from modern. Sprinkle places of ferns and cordates of the Jurassic period are now occupied by tropical forests, consisting mainly of the saga. Sugdans - a class of gone, prevailed in the green cover of the Earth of the Jurassic period. Now they meet in some places in the tropics and subtropics. Dinosaurs wandered under the seven of these trees. Externally, the segregatives are so similar to low (up to 10-18 m) palm trees, which was not initially identified as palm trees in the plant system.

In the Jurassic period, ginkgo - leaf falls (which is unusual for gone) trees with a crown, similar to oak, and with small fan-shaped leaves are also common. Only one species is preserved to this day - the ginko two-haired. The first cypress and, possibly firing appear in the yurt period. The coniferous forests of the Jurassic period were similar to modern.

In the Jurassic period on Earth established a moderate climate. Even the arid zones were rich in vegetation. Such conditions were ideally suitable for the reproduction of dinosaurs. They are distinguished by lizardous and poultomy.

The lizard moves were moving on four legs, had five fingers on the feet, they were fed on plants. Most of them had a long neck, a small head and a long tail. They had two brains: one small-in my head; The second is much greater largest - at the base of the tail.
The largest of the Jurassic dinosaurs was Brachiosaurus, which reached a length of 26 m, weighing about 50 tons. He had pillars, a small head, a thick long neck. Brachiosaurs lived on the shores of Jurassic lakes, fed water vegetation. Daily Brachiosaur needed at least halftone green mass.
The diplodok is an oldest reptile, its length was 28 m. He had a long thin neck and a long fat tail. Like Brachiosaur, the diplodok moved on four legs, the rear were longer than the front. The diplodok spent most of her life on the swamps and lakes, where she passed and escaped from predators.

The brontosaurus was relatively high, had a big hump on his back and a fat tail. Full-shaped little teeth densely located on the jaws of a small head. Inhabited brontosaur in swamps, on the shores of the lakes. The bronontosaur weighed about 30 tons and exceeded 20 and in length. Lizardonee dinosaurs (Zauropodi) were the largest famous land animals. All of them were roasting. Until recently, Paleontologists believed that such heavy creations were forced to carry out most of their lives in the water. It was believed that on land of his bertovy bones "would" be "under the severity of a colossal carcass. However, the discovery of recent years (in particular, the walking of the legs) suggest that Zauropodi preferred to wander in shallow water, they joined the solid soil. In relation to the size of the body, bronontosaurs had an extremely small brain, weighing no more than a pound. In the field of sacral vertebrae, brontosaurus there was an expansion of the spinal cord. Being much larger than the brain, it ruled the muscles of the hind limbs and the tail.

Poultom dinosaurs are divided into dongy and four-legged. Different in size and appearance, they felt predominantly vegetation, but predators appear among them.

Estate belongs. Steenzaws are especially abundant in North America, from where there are several types of these animals, reaching 6 meters long. The back was cool with a convex, the height of the animal reached 2.5 m. The body was massive, although the stentor moved on four legs, the front limbs had a much shorter rear. On the back, large bone plates that defended the vertebral pillar have risen in two rows. At the end of a short, thick tail used by animals to protect, there were two pairs of sharp spikes. The stegosaur was a vegetarian and had an exceptionally small head and, accordingly, a tiny brain, a little more walnut. Interestingly, the expansion of the spinal cord in the sacral region associated with the innervation of powerful hind limbs, for the diameter, much exceeded the brain.
There are many scaly lepidosavrov - small predators with bezvoid jaws.

In the Jurassic period, flying lizards appear for the first time. They flew with the help of a leathery shell stretched between a long finger brushes and bones of the forearm. Flying lizards were well adapted to flight. They had light tube bones. Extremely elongated external fifth finger of the front limbs consisted of four joints. The first finger had the appearance of a small bone or was completely absent. The second, the third and fourth fingers consisted of two, less often three bones and had claws. The hind limbs were quite developed. There were sharp claws at their ends. The skull of flying lizards was relatively large, as a rule, extended and pointed. At old lizards, cranial bones fused and skulls became similar to the skull of birds. The intercelion bone was sometimes smasted into an elongated toothless beak. In the teeth lizards, the teeth were simple and sat in the deepening. The largest teeth were in front. Sometimes they sticking to the side. It helped the lizards catch and hold prey. The spine animals consisted of 8 cervical, 10-15 dorsal, 4-10 sacral and 10-40 tail vertebrae. The chest was wide and had a high keel. The blades were long, pelvic bones have grown. The most characteristic representatives of flying lizards - Pterodactyl and Ramforinh.

Pterodactyls in most cases were eaten, different in size - from the size of the sparrow to the crows. They had wide wings and an extended narrow skull with a small number of teeth in front. Pterodactili lived in large flocks on the shores of the Lagoon of the Lagneury Sea. In the afternoon, they hunted, and with the onset of night they were hidden on trees or in rocks. The skin of the pterodactles was wrinkled and bare. They fed mainly by fish, sometimes sea lilies, mollusks, insects. In order to take off, the pterodactyls were forced to jump off the rocks or trees.
Ramforins had long tails, long narrow wings, a large skull with numerous teeth. Long teeth of different magnitude launched forward. The tail of the lizard ended the blade that served the steering wheel. Ramforins could take off from the ground. They settled on the banks of the rivers, lakes and seas, fed on insects and fish.

Flying lizards lived only in the Mesozoic Era, and their flourishing falls in the Landy Day. Their ancestors were, apparently, extinct ancient reptiles of pseudozukhi. Long-tailed forms appeared earlier than shorty. At the end of the Jurassic period, they died out.
It should be noted that the flying lizards were not ancestors of birds and bats. Flying lizards, birds and bats have occurred and developed every way, and there are no close relationships between them. The only general feature for them is the ability to fly. And although they all acquired this ability due to the change in the forelimbs, the differences in the structure of their wings convince us that they had completely different ancestors.

The sea of \u200b\u200bthe Jurassic period inhabited dolphin-like reptiles - ichthyosaurs. They had a long head, sharp teeth, big eyes surrounded by a bone ring. The length of the skull of some of them was 3 m, and the length of the body - 12 m. The ichthyosaurov limbs consisted of bone plates. Elbow, plus, brush and fingers differ little from each other. About one hundred bone plates supported a wide last. The shoulder and pelvic belt were weakly developed. There were several fins on the body. Ichthyosaurs were nipheral animals.

Along with Ithyozoors, Plesiosaur lived. Appeared in the Middle Triassa, already in the lower Yura reached a heyday, in chalk they were common in all seas. They were subdivided into two main groups: long-haired with a small head (actually Plesiosaurus) and short-sighted with a rather massive head (pliosewher). The limbs turned into powerful flippers who became the main navigation organ. More primitive Jurassic Pliosevras occur mainly from the territory of Europe. Plesiosaur from Lower Yura, reached a length of 3 m. These animals often went ashore for recreation. Plesiosaurs were not so deft in water like pliosewher. This disadvantage to a certain extent was replenished with the development of a long and very flexible neck, with the help of which Plesiosaurus could zilitally grab the prey. They fed mainly by fish and mollusks.
In the Jurassic period, new birth of fossil skulls appear, and at the end of the period - and modern turtles.
Chicken frog-shaped amphibians lived in fresh reservoirs.

In the Jurassic seas there were a lot of fish: bony, skates, sharks, cartilage, ganoids. They had an internal skeleton of flexible cartilage fabric, impregnated with calcium salts: a dense bone scaly cover, well-protected them from enemies, and jaws with strong teeth.
Ammonites, Belemnites, Sea Lilies were found from invertebrates in the Jurassic seas. However, in the Jurassic Ammonites, there were much less than in Triassa. Jurassic ammonites differ from Triassic and in their structure, with the exception of the Philosrass, completely unchanged when moving from Triass to Jura. Separate ammonite groups have retained to our time the pearl. Some animals were inhabited in the open sea, others - settled the bays and small intra-engineed seas.

Challenges are mollusks - Belemnitis - fleames in the Jurassic seas. Along with small copies there were real giants - up to 3 m long.
The remains of the internal shells of Belemnites, known as the "damn fingers", are found in the sediments of the Jurassic period.
In the seas of the Jurassic period, bivalve mollusks were also obtained, especially belonging to the oysters family. They begin to form oyster banks. Significant changes undergo marine hedgehogs settled on reefs. Along with those who lived to this day, round-sided symmetric irregular shapes lived. Their body was extended in one direction. Some of them had a jaw apparatus.

The Yursian seas were relatively shallow. The rivers brought muddy water into them, holding up gas exchange. Deep bays were filled with rotting residues and a sludge containing, a large amount of hydrogen sulfide. That is why, in such places, the remnants of animals listed by marine currents or waves are well preserved.
There is a lot of crustaceans: the pre-legged, the tenthellies, the leaf-legged crayfish, freshwater sponges, among insects - dragonflies, beetles, cicadas, bugs.

With Jurassic deposits, coal, plaster, oil, salt, nickel and cobalt are connected with.



160 million, years ago, a rich floral world provided foods of the giant zauropod to this time, and also gave the shelter to a huge number of small mammals and lizards. At this time, coniferous, ferns, horses, tree ferns and civilians were widespread.

A distinctive feature of the Jurassic period was the appearance and flourishing of giant lizard-dinosaurs, Zauropod, the largest of ever existed terrestrial animals. Despite its sizes, these dinosaurs were quite numerous.

Their petrified remains are found on all continents (with the exception of Antarctica) in rocks from the early Jurassic to the late Cretaceous periods, although they were the most common in the second half of the Jurassic period. At the same time, Zauropodi achieves their biggest sizes. They existed to the late Cretaceous period, when there were huge assavors among the terrestrial herbalists ("climbing dinosaurs").

Externally, all Zauropodi looked similar to each other: with an extremely long neck, an even longer tail, a massive, but relatively short torso, four colunopive legs and a relatively small head. Different species could change the position of the body and the proportion of individual parts. For example, such Sauropod of the Lateura period, like Brachiosaurs (Brachiosaurus - "Shoulder Lizard"), in the shoulder belt were higher than in pelvic, while the modern diplodoks (Diplodocus - "double process") were significantly lower, and at the same time Their hips rose over shoulders. Some types of Zauropod, such as Camarasaurs (Camarasaurus - "Chamber Lizard"), neck was relatively short, only a little longer than the body, and in others, for example, diplodovok, it was longer than two times.

Teeth and power supply

The external similarity of Zauropod masks an unexpectedly wide variety of structure of their teeth and, therefore, nutrition methods.

The Diplodok Skull helped the paleontologists to understand the way of nutrition of this dinosaur. The abrasion of teeth testifies that he broke the leaves either from below, or on top of himself.

Previously, in many dinosaur books, Zauropod mentioned "small, subtle teeth", but now it is known that the teeth of some of them, such as Kamarazavrov, were quite massive and durable to grind even very solid vegetable food, while long and thin, Reminded pencils of the teeth of the diploma really look unable to withstand significant loads that occur when chewing solid plants.

diplodocus. A long neck allowed him to "comb" food from the highest coniferous plants. It is believed that diplodoks lived in small fallen and fed on the shoots of trees.

In the study of the teeth of diplodes held in recent years in England, an unusual wear of their side surfaces was discovered. This nature of the abrasion of the teeth gave the key to understanding how these huge animals could eat. The lateral surface of the teeth could exist, only if something moved between them. Apparently, the diplodok enjoyed his teeth to break the beams of leaves and shoots, acting as a row, while his lower jaw could move a little back and forth. Most likely, when the animal shared the plants on the strips, captured below, moving heads up and forth, the lower jaw was shifted back (the upper teeth were located in front of the bottom), and when it pulled the above-tailed branches of high trees down and back, then nodded the lower jaw forward (The lower teeth were in front of the upper).

Brachiosaurus probably used its shorter, slightly pointed teeth for breaking only highly located leaves and shoots, since the orientation of his body in the vertical direction, due to the larger length of the front legs, made it difficult to power with plants growing low above the soil.

Narrow specialization

The kamarazavr, sizes, somewhat inferior to the giants mentioned above, possessed a relatively short and thicker neck and, most likely, was fed on the leaves located at the intermediate height between the power levels of Brachiosaurov and diplodok. It has had a high, rounded and more massive, compared to other zauropods, skull, as well as a more massive and durable lower jaw, which indicates the best ability to grind solid vegetable food.

The details of the anatomical structure described above are shown that within one ecological system (in the forests covering at this time most of the sushi), the barbats were fed by various vegetable foods, producing it in different ways at various levels. This is a division of food strategy and by type of food, which can be seen in the communities of herbivores and today, was called "tropical partitioning".

Brachiosaurs (Brachiosaurus) reached more than 25 m in length and 13 m in height. Their petrified remains and petrified eggs are found in East Africa and North America. Probably, they lived with herds like modern elephants.

The main difference between today's ecosystems of herbivore animals from the ecosystems of the late Jurassic period, in which the sashuctors dominated only the mass and height of animals. None of the modern herbivores, including elephants and giraffes, does not reach the height, comparable to the height of most major zauropod, and no of the modern land animals require such a huge amount of food as these giants.

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Some of the Zauropod lived in the Jurassic period reached fantastic sizes, for example, resembling Brachiosaurus Superzavr (SuperSaurus), whose remains found in the United States (Colorado) weighed, probably about 130 tons, that is, many times more than a large male of the African Elephant. But these supergiants shared sushi with hiding underground with tiny creatures that are not belonging to dinosales and even to reptiles. The Jurassic period was a time of existence of many numerical ancient mammals. These small, coated with fur, nipples and feeding young milk products were obtained by the name of the multi-vorted due to the unusual structure of their indigenous teeth: numerous, struggling together cylindrical "tubercles" formed uneven surfaces, perfectly adapted to chopping vegetation.

The multi-vorted were the most numerous and most diverse group of mammals of Jurassic and chalk periods. These are the only mammals of the Mesozoic era (the rest were specialized insectivore or carnivorous). They are known from Lateurish sediments, but the last finds show that they are close to a little-known group of extremely ancient mammals of the late Triassa, etc. haramide.

The structure of the skull and teeth of the Multi-bang was very reminded of today's rodents, they had two pairs of outstanding the incisors who attached to them the kind of typical rodent. Behind the cutters was not containing the gaps, followed by the very end of the little jaws they walked indigenous teeth. However, the nearest teeth of the Multi-fraternity teeth had an unusual structure. In fact, these were the first false (premolar) teeth with twisted sawdust edges.

Such an unusual structure of the teeth in the process of evolution re-occurred in some of the modern compounds, for example, in rat kangaroo in Australia, whose teeth are the same form and are in the same place of jaws as false teeth of the multi-bang. When chewing the food at the time of closure of the jaws, the Multi-tract could shift the lower jaw back, moving these sharp sawmifted teeth across the dietary fiber, and the long-cutters could be used to piercing dense plants or solid outdoor insect skeletons.

Lizardozaurus Megalosaurus (Megalosaurus) and his young, overtakers of a bird-made skelidosaurus. The scholarship is an ancient type of the dinosaurs of the Jurassic period with unevenly developed limbs, reaching 4 m in length. His spinal shell helped defend against predators.

The combination of sharp front incisors, served blades and chewing teeth means that the nutritional of the multi-vapor was quite universal. Today's rodents are also a very successful group of animals that flourishing in a wide variety of environmental systems and habitats. Most likely, it is a highly developed dental device that allows you to eat various foods, and caused the evolutionary success of the multi-tract. Their petrified remains, found on most continents, belong to various types: Some of them, apparently, lived on trees, while others resembling modern gerbils were probably adapted to existence in a arid desert climate.

Change ecosystems

The existence of multi-tract covers the period of 215 million years, extending from the late Triass through the entire Mesozoic Era to the oligocene era of the Cenozoic Era. This phenomenal success is unique to mammals and most terrestrial tetrapodes, makes multiparty the most successful group of mammals.

The ecosystems of small animals of the Jurassic period also included small lizards of a wide variety of species and even their water forms.

Thrinadoxon (View Cosnontt). His limbs were slightly outlined to the parties, and not located under the torso, like modern mammals.

They and those who lived to this time rarely encountered reptiles of the Synapsid group ("visually-shaped reptiles"), tritilodonts, lived at one time and in the same ecosystems as multiparty mammals. Tritiliodonts were a numerous and widespread type throughout the total trias period, but, like other zinosnonts, were very damaged during late-grade extinction. This is the only group of cycosnonts, preserved in the Jurassic period. In appearance, they, as well as multiparty mammals, were very reminded of modern rodents. That is, a substantial part of the ecosystems of small animals of the Jurassic period consisted of animals resembling rodents: thrilodonts and multi-bang mammals.

Multiparthigh mammals were certainly the most numerous and diverse group of the Mammals of the Jurassic period, but at that time there were other groups of mammals, including: morganacodonts (ancient mammals), amphilestids, permuride (PERAMURIDS), amphitherid (amphitherids), Tinodonts (AmphiTherids Tinodontids) and Docodonts (Docodonts). All these small mammals looked like mice or earthamov. At the subcode, for example, developed peculiar, wide indigenous teeth, well adapted for chewing solid seeds and nuts.

At the end of the Jurassic period, significant changes occurred at the other end of the size scale in the group of large two-legged predatory dinosaurs, the teropod presented at this time by allosaurs (Auosaurus - "strange lizards"). At the end of the Jurassic period, a group of teropod was alone, called spinosauride ("spiny or spiked lizards"), a distinctive feature of which was a comb from long process of torso vertebrae, which, perhaps, as a dorsal sail in some pelicosaurs, helped them adjust the body temperature. Such spinosaurides like Siamosaurus ("Lizard of Siam"), the length of which reached 12 m, together with other teropods divided the niche of the largest predators in the ecosystems.

At the spinosauride there were unemployed teeth and elongated, less massive compared to other teropods of this time, skull. These features of the structure indicate that they differed in the way of nutrition, they differ from such a teropod such as Allosavra, EustreptoSpondylus ("Strong curved vertebrae") and Ceratosaurs (Ceratosaurus - "Horned Lizard"), and most likely hunted another prey.

Poultry-like dinosaurs

In lateure, other types of teropod arose, very distinguished from such huge, weighing up to 4 tons, predators like Allosavra. These were ornithyndides - long-legged, long-haired, with small heads, toothless omnivorous animals, strikingly reminiscent of modern ostrichs, which is why they received their name "bird imitators".

The very first ornithride, elaphrosaums ("light lizard"), from the Last Day, North America had light, hollow bones and toothless beaks, and its limbs, both the rear and the front, were shorter than that of later ornithminide of the chalk period, and, Accordingly, it was a slower animal.

Another environmentally important group of dinosaurs, which arose in the late Jurassic period, - Nodozavra, four-legged dinosaurs with massive, coated bodies, short, relatively thin limbs, a narrow head with an elongated face (but with massive jaws), with small leaf teeth and a horn beak. Their name ("noded lizards") is associated with covering skin bone plates, protruding vertebral treasures and scattered on skin growths that served as protection against attacks of predators. The widespread dissemination of the nodozavra received only in the chalk period, and in the Landyury time they, along with huge, eating shoots of trees, were only one of the elements of the travelers of herbivore dinosaurs who served a variety of huge predators.