Jurassic period history. Geological period
Jurassic period most famous of all periods Mesozoic era. More likely, such fame Jurassic period acquired thanks to the film "Jurassic Park".
Jurassic tectonics:
At first Jurassic period the single supercontinent Pangea began to break up into separate continental blocks. Shallow seas formed between them. Intense tectonic movements at the end Triassic and at the beginning Jurassic periods contributed to the deepening of large bays, which gradually separated Africa and Australia from Gondwana. The gulf between Africa and America has deepened. Depressions formed in Eurasia: German, Anglo-Paris, West Siberian. The Arctic Sea flooded the northern coast of Laurasia. It was due to this that the climate of the Jurassic period became more humid. During the Jurassic period The outlines of the continents begin to form: Africa, Australia, Antarctica, North and South America. And although they are located differently than now, they were formed precisely in Jurassic period.
This is what the Earth looked like at the end of the Triassic - the beginning Jurassic period
about 205 - 200 million years ago
This is what the Earth looked like at the end of the Jurassic period around 152 million years ago.
Jurassic climate and vegetation:
Volcanic activity of the end of the Triassic - the beginning Jurassic period caused sea transgression. The continents were divided and the climate in Jurassic period became wetter than in the Triassic. On the site of deserts of the Triassic period, in Jurassic period lush vegetation grew. Huge areas were covered with lush vegetation. Forests Jurassic period consisted mainly of ferns and gymnosperms.
Warm and humid climate Jurassic period contributed to the rapid development flora planets. Ferns, conifers and cycads formed vast swampy forests. Araucarias, thujas, and cycads grew on the coast. Ferns and horsetails formed extensive forested areas. At first Jurassic period, about 195 million years ago Throughout the northern hemisphere, the vegetation was quite monotonous. But already starting from the middle of the Jurassic period, about 170-165 million years ago, two (conditional) plant belts were formed: northern and southern. In the northern plant belt ginkgo and herbaceous ferns predominated. IN Jurassic period ginkgos were very widespread. Groves of ginkgo trees grew throughout the belt.
The southern plant belt was dominated by cycads and tree ferns.
Ferns Jurassic period and are still preserved in some corners today wildlife. Horsetails and mosses were almost no different from modern ones. Places where ferns and cordaites grow Jurassic period now occupied by tropical forests, consisting mainly of cycads. Cycads are a class of gymnosperms that predominated in the green cover of the Earth Jurassic period. Nowadays they are found here and there in the tropics and subtropics. Dinosaurs roamed under the shade of these trees. Externally, cycads are so similar to low (up to 10-18 m) palm trees that they were even initially identified as palm trees in the plant system.
IN Jurassic period Ginkgos are also common - deciduous (which is unusual for gymnosperms) trees with an oak-like crown and small fan-shaped leaves. Only one species has survived to this day - Ginkgo biloba. The first cypress and, possibly, spruce trees appear precisely during the brisk period. Coniferous forests
Jurassic period were similar to modern ones.
Land animals Jurassic period:
Jurassic period - Dawn of the Age of Dinosaurs. It was the lush development of vegetation that contributed to the emergence of many species of herbivorous dinosaurs. The increase in the number of herbivorous dinosaurs gave impetus to the increase in the number of predators. Dinosaurs settled all over the land and lived in forests, lakes, and swamps. The range of differences between them is so great that family ties between them are established with great difficulty. Variety of dinosaur species in Jurassic period it was great. They could be the size of a cat or chicken, or they could reach the size of huge whales.
One of the fossil creatures Jurassic period, combining the characteristics of birds and reptiles, is Archeopteryx, or first bird. His skeleton was first discovered in the so-called lithographic shales in Germany. The discovery was made two years after the publication of Charles Darwin's On the Origin of Species and became a strong argument in favor of the theory of evolution. Archeopteryx still flew quite poorly (gliding from tree to tree), and was approximately the size of a crow. Instead of a beak, it had a pair of toothy ones, although weak jaws. It had free fingers on its wings (of modern birds, only hoatzin chicks have them).
Kings of the Jurassic Sky:
IN Jurassic period Winged lizards - pterosaurs - reigned supreme in the air. They appeared in the Triassic, but their heyday was precisely Jurassic period Pterosaurs were represented by two groups pterodactyls And Rhamphorhynchus .
Pterodactyls were in most cases tailless, varying in size - from the size of a sparrow to a crow. They had wide wings and a narrow skull elongated forward with a small number of teeth in the front. Pterodactyls lived in large flocks on the shores of the lagoons of the Late Jurassic Sea. During the day they hunted, and at nightfall they hid in trees or rocks. The skin of pterodactyls was wrinkled and bare. They ate mainly fish or carrion, sometimes sea lilies, mollusks, and insects. In order to fly, pterodactyls were forced to jump from cliffs or trees.
IN Jurassic period the first birds or something in between birds and lizards appear. Creatures that appeared in Jurassic period and having the properties of lizards and modern birds are called Archeopteryx. The first birds were Archeopteryx, the size of a pigeon. Archeopteryx lived in forests. They ate mainly insects and seeds.
But Jurassic period is not limited to just animals. Thanks to climate change and rapid development of flora Jurassic period, the evolution of insects accelerated dramatically, and as a result, the Jurassic landscape was eventually filled with the endless buzzing and crackling sounds of many new species of insects crawling and flying everywhere. Among them were the predecessors of modern ants, bees, earwigs, flies and wasps.
Masters of the Jurassic Seas:
As a result of the split of Pangea, Jurassic period, new seas and straits were formed, in which new types of animals and algae developed.
Compared to the Triassic, in Jurassic period The population of the seabed has changed greatly. Bivalves displace brachiopods from shallow waters. Brachiopod shells are replaced by oysters. Bivalve mollusks fill all life niches of the seabed. Many stop collecting food from the ground and switch to pumping water using their gills. In warm and shallow seas Jurassic period Other important events also took place. IN Jurassic period a new type of reef community is emerging, approximately the same as what exists now. It is based on six-rayed corals that appeared in the Triassic. The resulting giant coral reefs sheltered numerous ammonites and new species of belemnites (old relatives of today's octopuses and squids). They also housed many invertebrates, such as sponges and bryozoans (sea mats). Gradually, fresh sediment accumulated on the seabed.
On land, in lakes and rivers Jurassic period There were many different species of crocodiles that spread widely across the globe. There were also saltwater crocodiles with long snouts and sharp teeth for catching fish. Some of their varieties even grew flippers instead of legs to make swimming more convenient. The tail fins allowed them to develop greater speed in the water than on land. New species of sea turtles have also appeared.
All dinosaurs of the Jurassic period
Herbivorous dinosaurs:
And was replaced by chalk, and had a duration of about 56 million years.
Geography and climate
During the Jurassic period, the supercontinent Pangea began to split into two separate continents:
- the northern part known as Laurasia (which eventually split into North America and Eurasia, opening up the basins to Atlantic Ocean, and the Gulf of Mexico)
- the southern part - Gondwanaland - drifted east (and eventually divided into Antarctica, Madagascar, India and Australia, and its West Side, formed Africa and South America).
This process of Pangea's separation, along with warmer global temperatures, allowed reptiles such as dinosaurs to diversify and dominate the Earth for long periods of time.
Plant life
During the Mesozoic era, plants developed the ability to lead a terrestrial lifestyle and not be limited only to the oceans. By the beginning of the Jurassic, life came from bryophytes, low-growing bryophytes and liverworts, which had no vascular tissue and were limited to wet, marshy areas.
Ginkgo trees
Ferns and gingaceae, which have roots and vascular tissue for transporting water, and nutrients, and also reproducing by spores, were the dominant plants of the Early Jurassic. Appeared during the Jurassic period new way plant propagation. Gymnosperms such as coniferous trees, have developed pollen, which is distributed over long distances by the wind and pollinates female cones. This method of reproduction made it possible to significantly increase the number of gymnosperms by the end of the Jurassic period. Flowering plants did not evolve before Cretaceous period.
Age of Dinosaurs
As depicted in the movie Jurassic Park, reptiles were the dominant animal life form during the Jurassic period. They overcame evolutionary obstacles that limited . Reptiles had strong, ossified skeletons with advanced muscular systems to support and move the body. Some of the largest animals that ever lived were the dinosaurs of the Jurassic period. Reptiles could also develop amniotic eggs that were incubated on land.
sauropods
Sauropods (lizard-footed dinosaurs) are herbivorous quadrupeds with long necks and heavy tails. Many sauropods, such as brachiosaurs, were huge. Representatives of some genera had a body length of about 25 m, and weight ranged from 50-100 tons, which makes them the largest land animals that have ever existed on Earth. Their skulls were relatively small, with nostrils raised high towards the eyes. Such small skulls meant very small brains. Despite their small brains, this group of animals flourished during the Jurassic period and had a wide geographic distribution. Sauropod fossils have been found on every continent except Antarctica. Other famous dinosaurs The Jurassic includes stegosaurs and flying pterosaurs.
Carnosaurs were one of the main predators of the Mesozoic era. The genus Allosaurus was one of the most widespread carnosaurs in North America. They are similar to later tyrannosaurs, although studies have shown that they have little in common. Allosaurs had strong hind limbs, heavy front legs and long jaws.
Early mammals
Adelobazilevs
Dinosaurs may have been the dominant land animals, but they were not the only fauna. Early mammals were mostly very small herbivores or insectivores, and did not compete with larger reptiles. Adelobasileus is a predatory ancestor of mammals. He had a special structure of the inner ear and jaws. This animal appeared at the end of the Triassic period.
In August 2011, scientists from China announced the discovery of Yuramaya. This tiny mid-Jurassic animal has caused excitement among scientists because it was a clear ancestor placental mammals, indicating that mammals evolved much earlier than previously thought.
Sea life
Plesiosaur
The Jurassic period was also very diverse. The largest sea predators there were plesiosaurs. These carnivorous marine reptiles typically had wide bodies and long necks with four flipper-shaped limbs.
Ichthyosaur is a marine reptile that was most common in the Early Jurassic period. Because some fossils have been found with smaller individuals of their species inside their bodies, it is suggested that these animals may have been among the first to experience internal pregnancy and give birth to live young.
Cephalopods were also widespread during the Jurassic period and included the ancestors of modern squids. Among the most beautiful fossils sea life Spiral-shaped shells of ammonites can be distinguished.
, conglomerates formed in a variety of conditions.
Jurassic System Division
Jurassic system is divided into 3 departments and 11 tiers:
| system | Department | tier | Age, million years ago | |
|---|---|---|---|---|
| Chalk | Lower | Berriasian | less | |
| Yura | Upper (malm) |
Titonian | 152,1-145,0 | |
| Kimmeridge | 157,3-152,1 | |||
| Oxford | 163,5-157,3 | |||
| Average (dogger) |
Callovian | 166,1-163,5 | ||
| Bathian | 168,3-166,1 | |||
| Bayocian | 170,3-168,3 | |||
| Aalensky | 174,1-170,3 | |||
| Lower (lias) |
Toarsky | 182,7-174,1 | ||
| Pliensbachian | 190,8-182,7 | |||
| Sinemyursky | 199,3-190,8 | |||
| Hettangian | 201,3-199,3 | |||
| Triassic | Upper | Rhetic | more | |
| Divisions are given according to IUGS as of April 2016 | ||||
Geological events
213-145 million years ago, the single supercontinent Pangea began to break up into separate continental blocks. Shallow seas formed between them.
Climate
The climate in the Jurassic period was humid and warm (and by the end of the period - arid in the equator region).
Vegetation
During the Jurassic, vast areas were covered with lush vegetation, primarily diverse forests. They mainly consisted of ferns and gymnosperms.
Land animals
One of the fossil creatures that combines the characteristics of birds and reptiles is Archeopteryx, or the first bird. His skeleton was first discovered in the so-called lithographic shales in Germany. The discovery was made two years after the publication of Charles Darwin's work "On the Origin of Species" and became a strong argument in favor of the theory of evolution - it was initially considered a transitional form from reptiles to birds (in fact, it was a dead-end branch of evolution, not directly related to real birds) . Archeopteryx flew rather poorly (gliding from tree to tree), and was approximately the size of a crow. Instead of a beak, it had a pair of toothy, albeit weak, jaws. It had free fingers on its wings (of modern birds, only hoatzin chicks have them).
During the Jurassic period, small, furry, warm-blooded animals called mammals lived on Earth. They live next to dinosaurs and are almost invisible against their background. During the Jurassic period, the division of mammals into monotremes, marsupials and placentals occurred.
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Notes
Literature
- Iordansky N. N. Development of life on earth. - M.: Education, 1981.
- Karakash N. I. ,.// Encyclopedic Dictionary of Brockhaus and Efron: in 86 volumes (82 volumes and 4 additional). - St. Petersburg. , 1890-1907.
- Koronovsky N.V., Khain V.E., Yasamanov N.A. Historical geology: Textbook. - M.: Academy, 2006.
- Ushakov S.A., Yasamanov N.A. Continental drift and climates of the Earth. - M.: Mysl, 1984.
- Yasamanov N.A. Ancient climates of the Earth. - L.: Gidrometeoizdat, 1985.
- Yasamanov N.A. Popular paleogeography. - M.: Mysl, 1985.
Links
- - Site about the Jurassic period, a large library of paleontological books and articles.
| ← | P A l e O h O th |
Mesozoic (252.2-66.0 million years ago) | TO A th n O h O th |
→ | ||
|---|---|---|---|---|---|---|
| ← | Triassic (252,2-201,3) |
Jurassic period (201,3-145,0) |
Cretaceous period (145,0-66,0) |
→ | ||
An excerpt characterizing the Jurassic period
Yes, happy Napoleon,Having learned through experience what Bagration is like,
Alkidov doesn’t dare bother the Russians any more...”
But he had not yet finished the verses when the loud butler announced: “The food is ready!” The door opened, a Polish voice thundered from the dining room: “Roll out the thunder of victory, rejoice, brave Ross,” and Count Ilya Andreich, looking angrily at the author, who continued to read poetry, bowed to Bagration. Everyone stood up, feeling that dinner was more important than poetry, and again Bagration went to the table ahead of everyone. In the first place, between the two Alexanders - Bekleshov and Naryshkin, which also had significance in relation to the name of the sovereign, Bagration was seated: 300 people were seated in the dining room according to rank and importance, who was more important, closer to the guest being honored: as naturally as water spills deeper there, where the terrain is lower.
Just before dinner, Count Ilya Andreich introduced his son to the prince. Bagration, recognizing him, said several awkward, awkward words, like all the words he spoke that day. Count Ilya Andreich joyfully and proudly looked around at everyone while Bagration spoke with his son.
Nikolai Rostov, Denisov and his new acquaintance Dolokhov sat down together almost in the middle of the table. Opposite them, Pierre sat down next to Prince Nesvitsky. Count Ilya Andreich sat opposite Bagration with other elders and treated the prince, personifying Moscow hospitality.
His labors were not in vain. His dinners, fast and fast, were magnificent, but he still could not be completely calm until the end of dinner. He winked at the barman, whispered orders to the footmen, and, not without excitement, awaited each dish he knew. Everything was amazing. On the second course, along with the gigantic sterlet (when Ilya Andreich saw it, he blushed with joy and shyness), the footmen began popping the corks and pouring champagne. After the fish, which made some impression, Count Ilya Andreich exchanged glances with the other elders. - “There will be a lot of toasts, it’s time to start!” – he whispered and took the glass in his hands and stood up. Everyone fell silent and waited for him to speak.
- Health of the Emperor! - he shouted, and at that very moment his kind eyes were moistened with tears of joy and delight. At that very moment they started playing: “Roll the thunder of victory.” Everyone stood up from their seats and shouted hurray! and Bagration shouted hurray! in the same voice with which he shouted on the Shengraben field. The enthusiastic voice of young Rostov was heard from behind all 300 voices. He almost cried. “The health of the Emperor,” he shouted, “hurray!” – Having drunk his glass in one gulp, he threw it on the floor. Many followed his example. And the loud screams continued for a long time. When the voices fell silent, the footmen picked up the broken dishes, and everyone began to sit down, smiling at their shouts and talking to each other. Count Ilya Andreich stood up again, looked at the note lying next to his plate and proposed a toast to the health of the hero of our last campaign, Prince Pyotr Ivanovich Bagration and again Blue eyes The count was moistened with tears. Hooray! the voices of 300 guests shouted again, and instead of music, singers were heard singing a cantata composed by Pavel Ivanovich Kutuzov.
“All obstacles for the Russians are in vain,
Bravery is the key to victory,
We have Bagrations,
All enemies will be at your feet,” etc.
The singers had just finished when more and more toasts followed, during which Count Ilya Andreich became more and more emotional, and even more dishes were broken, and even more shouting. They drank to the health of Bekleshov, Naryshkin, Uvarov, Dolgorukov, Apraksin, Valuev, to the health of the foremen, to the health of the manager, to the health of all club members, to the health of all club guests, and finally, separately to the health of the founder of the dinner, Count Ilya Andreich. At this toast, the count took out a handkerchief and, covering his face with it, completely burst into tears.
Pierre sat opposite Dolokhov and Nikolai Rostov. He ate a lot and greedily and drank a lot, as always. But those who knew him briefly saw that some big change had taken place in him that day. He was silent the entire time of dinner and, squinting and wincing, looked around him or, stopping his eyes, with an air of complete absent-mindedness, rubbed the bridge of his nose with his finger. His face was sad and gloomy. He seemed to not see or hear anything happening around him, and was thinking about something alone, heavy and unresolved.
This unresolved question that tormented him, there were hints from the princess in Moscow about Dolokhov’s closeness to his wife and this morning the anonymous letter he received, in which it was said with that vile playfulness that is characteristic of all anonymous letters that he sees poorly through his glasses, and that his wife’s connection with Dolokhov is a secret only to him. Pierre decidedly did not believe either the princess’s hints or the letter, but he was now afraid to look at Dolokhov, who was sitting in front of him. Every time his gaze accidentally met Dolokhov’s beautiful, insolent eyes, Pierre felt something terrible, ugly rising in his soul, and he quickly turned away. Unwittingly remembering everything that had happened with his wife and her relationship with Dolokhov, Pierre saw clearly that what was said in the letter could be true, could at least seem true if it did not concern his wife. Pierre involuntarily recalled how Dolokhov, to whom everything was returned after the campaign, returned to St. Petersburg and came to him. Taking advantage of his carousing friendship with Pierre, Dolokhov came directly to his house, and Pierre accommodated him and lent him money. Pierre recalled how Helen, smiling, expressed her displeasure that Dolokhov lived in their house, and how Dolokhov cynically praised the beauty of his wife, and how from that time until his arrival in Moscow he was not separated from them for a minute.
“Yes, he is very handsome,” thought Pierre, I know him. It would be a special delight for him to dishonor my name and laugh at me, precisely because I worked for him and looked after him, helped him. I know, I understand what salt this should give to his deception in his eyes, if it were true. Yes, if it were true; but I don’t believe, I don’t have the right and I can’t believe.” He recalled the expression that Dolokhov's face took on when moments of cruelty came over him, like those in which he tied up a policeman with a bear and set him afloat, or when he challenged a man to a duel without any reason, or killed a coachman's horse with a pistol. . This expression was often on Dolokhov's face when he looked at him. “Yes, he’s a brute,” thought Pierre, it doesn’t mean anything to him to kill a man, it must seem to him that everyone is afraid of him, he must be pleased with this. He must think that I am afraid of him too. And really I’m afraid of him,” thought Pierre, and again with these thoughts he felt something terrible and ugly rising in his soul. Dolokhov, Denisov and Rostov were now sitting opposite Pierre and seemed very cheerful. Rostov chatted merrily with his two friends, one of whom was a dashing hussar, the other a famous raider and rake, and occasionally glanced mockingly at Pierre, who at this dinner impressed with his concentrated, absent-minded, massive figure. Rostov looked at Pierre unkindly, firstly, because Pierre, in his hussar eyes, was a rich civilian, the husband of a beauty, generally a woman; secondly, because Pierre, in the concentration and distraction of his mood, did not recognize Rostov and did not respond to his bow. When they began to drink the sovereign's health, Pierre, lost in thought, did not get up and take the glass.
Jurassic period (Jurassic)- middle (second) period of the Mesozoic era. Began 201.3 ± 0.2 million years ago, ended 145.0 million years ago. Thus it continued for about 56 million years. Sediment complex ( rocks), corresponding to a given age, is called the Jurassic system. In different regions of the planet, these deposits differ in composition, genesis, and appearance.
For the first time, deposits of this period were described in the Jura (mountains in Switzerland and France); This is where the name of the period came from. The deposits of that time are quite diverse: limestones, clastic rocks, shales, igneous rocks, clays, sands, conglomerates, formed in a variety of conditions.
Flora
In the Jurassic, vast areas were covered with lush vegetation, primarily diverse forests. They mainly consisted of ferns and gymnosperms.
Cycads are a class of gymnosperms that predominated in the green cover of the Earth. Nowadays they are found in the tropics and subtropics. Dinosaurs roamed under the shade of these trees. Externally, cycads are so similar to low (up to 10-18 m) palm trees that even Carl Linnaeus placed them among palm trees in his plant system.
During the Jurassic period, groves of gingkovic trees grew throughout the then temperate zone. Ginkgos are deciduous (unusual for gymnosperms) trees with an oak-like crown and small fan-shaped leaves. Only one species has survived to this day - ginkgo biloba.
The conifers were very diverse, similar to modern pines and cypresses, which flourished at that time not only in the tropics, but had already mastered temperate zone. The ferns gradually disappeared.
Fauna
Marine organisms
Compared to the Triassic, the population of the seabed has changed greatly. Bivalves displace brachiopods from shallow waters. Brachiopod shells are replaced by oysters. Bivalve mollusks fill all life niches of the seabed. Many stop collecting food from the ground and switch to pumping water using their gills. A new type of reef community is emerging, approximately the same as what exists now. It is based on six-rayed corals that appeared in the Triassic.
Land animals of the Jurassic period
One of the fossil creatures that combines the characteristics of birds and reptiles is Archeopteryx, or the first bird. His skeleton was first discovered in the so-called lithographic shales in Germany. The discovery was made two years after the publication of Charles Darwin's On the Origin of Species and became a strong argument in favor of the theory of evolution. Archeopteryx still flew quite poorly (gliding from tree to tree), and was approximately the size of a crow. Instead of a beak, it had a pair of toothy, albeit weak, jaws. It had free fingers on its wings (of modern birds, only hoatzin chicks have them).
During the Jurassic period, small, furry, warm-blooded animals called mammals lived on Earth. They live next to dinosaurs and are almost invisible against their background. In the Jurassic, mammals were divided into monotremes, marsupials and placentals.
Dinosaurs (English Dinosauria, from ancient Greek δεινός - terrible, terrible, dangerous and σαύρα - lizard, lizard) lived in forests, lakes, and swamps. The range of differences between them is so great that family ties between them are established with great difficulty. There were dinosaurs ranging in size from a cat to a whale. Different types dinosaurs could walk on two or four limbs. Among them were both predators and herbivores.
Scale
| Geochronological scale | |||
|---|---|---|---|
| Eon | Era | Period | |
| F A n e R O h O th | Cenozoic | Quaternary | |
| Neogene | |||
| Paleogene | |||
| Mesozoic | Chalk | ||
| Yura | |||
| Triassic | |||
| Paleozoic | Permian | ||
| Carbon | |||
| Devonian | |||
| Silur | |||
| Ordovician | |||
| Cambrian | |||
| D O To e m b R And th | P R O T e R O h O th | Neo- Proterozoic | Ediacaran |
| Cryogenium | |||
| Tony | |||
| Meso- Proterozoic | Stenius | ||
| Ectasy | |||
| Kalimium | |||
| Paleo- Proterozoic | Staterius | ||
| Orosirium | |||
| Riasiy | |||
| Siderius | |||
| A R X e th | Neoarchaean | ||
| Mesoarchean | |||
| Paleoarchaean | |||
| Eoarchaean | |||
| Katarhey | |||
Jurassic System Division
The Jurassic system is divided into 3 divisions and 11 tiers:
| system | Department | tier | Age, million years ago | |
|---|---|---|---|---|
| Chalk | Lower | Berriasian | less | |
| Jurassic period | Upper (malm) | Titonian | 145,0-152,1 | |
| Kimmeridge | 152,1-157,3 | |||
| Oxford | 157,3-163,5 | |||
| Average (dogger) | Callovian | 163,5-166,1 | ||
| Bathian | 166,1-168,3 | |||
| Bayocian | 168,3-170,3 | |||
| Aalensky | 170,3-174,1 | |||
| Lower (lias) | Toarsky | 174,1-182,7 | ||
| Pliensbachian | 182,7-190,8 | |||
| Sinemyursky | 190,8-199,3 | |||
| Hettangian | 199,3-201,3 | |||
| Triassic | Upper | Rhetic | more | |
| Subsections are given according to IUGS as of January 2013 | ||||
Belemnite rostra Acrofeuthis sp. Early Cretaceous, Hauterivian
Shells of the brachiopod Kabanoviella sp. Early Cretaceous, Hauterivian
Shell of the bivalve Inoceramus aucella Trautschold, Early Cretaceous, Hauterivian
Skeleton of the saltwater crocodile Stenosaurus, Steneosaurus boltensis Jaeger. Early Jurassic, Germany, Holtzmaden. Among saltwater crocodiles, the Thalattosuchus stenosaurus was the least specialized form. It did not have flippers, but ordinary five-fingered limbs, like those of land animals, although somewhat shortened. In addition, a powerful bone armor made of plates has been preserved on the back and belly.
Three of the specimens presented on the wall (the crocodile Sthenosaurus and two ichthyosaurs - Stenopterygium and Eurynosaurus) were found at one of the world's largest sites of Early Jurassic marine fauna GOLZMADEN (about 200 million years ago; Bavaria, Germany). For several centuries, slate was mined here and used as a building and decorative material.
At the same time, a huge number of remains of invertebrate fish, ichthyosaurs, plesiosaurs and crocodiles were discovered. More than 300 ichthyosaur skeletons alone have been recovered.
Small flying lizards - Sordes were numerous in the vicinity of Lake Karatau. They probably ate fish and insects. Some specimens of Sordes have preserved remains of hair, which is extremely rare in other localities.
Thecodonts- a group pre-new for other archosaurs. The first representatives (1,2) were terrestrial predators with widely spaced limbs. In the process of evolution, some thecodonts acquired a semi-vertical and vertical paw position with a four-legged mode of movement (3,5,6), others - in parallel with the development of bipedality (2,7,8). Most thecodonts were terrestrial, but some of them led an amphibiotic lifestyle (6).
Crocodiles close to thecodonts. Early crocodiles (1,2,9) were terrestrial animals, marine forms with flippers and a caudal fin also existed in the Mesozoic (10), and modern crocodiles are adapted to an amphibiotic lifestyle (11).
Dinosaurs- the central and most striking group of archosaurs. Large predatory carnosaurs (14,15) and small predatory cepurosaurs (16,17,18), as well as herbivorous ornithopods (19,20,21,22) were bipedal. Others used quadrupedal locomotion: sauropods (12,13), ceratopsians (23), stegosaurs (24) and antiposaurs (25). Sauropods and duck-billed dinosaurs (21) adopted an amphibiotic lifestyle to varying degrees. One of the most highly organized among archosaurs were flying lizards (26,27,28), which had wings with a flying membrane, hair and, possibly, constant temperature bodies.
Birds- are considered direct descendants of Mesozoic archosaurs.
Small land crocodiles, united in the group of notosuchia (Notosuchia), were widespread in Africa and South America throughout the Cretaceous period.
Part of the skull sea lizard- pliosaur. Pliosaurus cf. grandis Owen, Late Jurassic, Volga region. Pliosaurs, as well as their closest relatives - plesiosaurs, were perfectly adapted to aquatic environment. They were distinguished by a large head, short neck and long, powerful, flipper-like limbs. Most pliosaurs had dagger-shaped teeth, and they were the most dangerous predators of the Jurassic seas. This sample, 70 cm long, is only the anterior third of the pliosaur skull, and the total length of the animal was 11-13 m. The pliosaur lived 150-147 million years ago.
Larva of the coptoclava beetle, Coptoclava longipoda Ping. This is one of the most dangerous predators In the lake.
Apparently, in the middle of the Cretaceous period, conditions in the lakes changed greatly and many invertebrates had to move into rivers, streams or temporary reservoirs (caddis flies, the larvae of which build tube houses from grains of sand; flies, bivalves). Bottom sediments of these reservoirs are not preserved, flowing waters wash them away, destroying the remains of animals and plants. Organisms that migrate to such habitats disappear from the fossil record.
Houses made of grains of sand, which were built and carried by caddisfly larvae, are very characteristic of Early Cretaceous lakes. In later eras, such houses are found mainly in flowing waters
Larvae of the caddisfly Terrindusia (reconstruction)
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