What is the Cenozoic era. Quaternary period of the Cenozoic era: animals, plants, climate
The Quaternary period of the Cenozoic era was marked by a large-scale glaciation, which had a huge impact on the development of life on the planet. As the glaciers advanced, the climatic barrier of life slowly moved south, the wild vegetation of the Cenozoic also retreated south. In the interglacial epochs, it again returned to its original territories. True, in some regions of the world, the return of vegetation was often blocked by mountain ranges, which predetermined the extinction of many plants in the temperate zone. Their fate was shared by some groups of animals, directly or indirectly dependent on certain types of vegetation.
Many representatives of the animal world managed to adapt to the intensified cold weather, acquiring thick hair. The Pleistocene era is characterized by a wide distribution of saber-toothed cats, marsupials and cave lions. In the Pleistocene, the first people appeared, and many large mammals, on the contrary, began to die out. Cooling alternated with warming. During the ice age, three zones of vegetation were clearly distinguished on the planet: tundra, steppe and taiga. They were located south of the advancing glaciers, in an area 200-320 km wide. Thus, repeated glaciations significantly devastated the flora of the planet, and the return of heat-loving plants from south to north was hampered by mountain ranges that acted as barriers to the settlement of vegetation.
Nevertheless, in the warmest interglacial epochs of the Quaternary period, broad-leaved forests were widespread, dominated by oak, beech, linden, maple, ash, hornbeam, alder, walnut and hawthorn. During a large-scale glaciation, water vapor condensed in the form of snow, but the melting of ice and snow annually produced less water than snow fell. The gradual accumulation of ice reserves on land contributed to lowering the level of the World Ocean. Therefore, in the Quaternary period, special land bridges arose between continental Europe and the British Isles, Asia and North America, the Amur region and Sakhalin, as well as between the Indochina peninsula and the islands of the Sunda archipelago.
These land bridges carried out the exchange of animals and plants. At the same time, it was the absence of a connecting link between Asia and Australia that preserved the life of cloacal and marsupials, which, even in the Tertiary period, were completely replaced by placental mammals on other continents of the planet. In the Quaternary period, various groups of mammals and, in particular, elephants met. The largest of them lived in forests and had a shoulder height of over 4 m. In the Siberian tundra, the cold-loving mammoth Mammuthus primigenius, covered with thick and long reddish hair, occupied a dominant position. During one of the ice ages, mammoths probably crossed the ice of the Bering Strait and settled throughout North America. Skeletons of heavy-weight mastodons are often found today in this region of the world.
Prominent representatives of the fauna of that time are large woolly rhinos, which lived in the tundra next to mammoths during the glaciation era. There was also a resettlement of horses, whose homeland is North America. Moving through Asia and Europe, they gradually settled around the world. It is noteworthy that in North America itself, horses died out by the end of the Pleistocene and returned there only with the European conquerors. It is a pity that we were never able to see them, because these animals had a delightful appearance. Today, many fans of the world of fauna like to put pictures of animals in photo frames and hang them on their walls. But it is better, of course, to insert photos of loved ones there.
Numerous subspecies of the wild horse inhabited the savannas of the European continent as early as the beginning of the Quaternary. Among the ruminant artiodactyls, one can distinguish a huge large-mouthed deer, the distance between the horns of which reached 3 m. Musk oxen, primitive bison and aurochs, the ancestors of modern domestic bulls, bred in large numbers. In the Quaternary period, our planet was also inhabited by numerous predators, among them we can note the huge cave bears Ursus spelaeus, the saber-toothed tigers Machairodus, whose long fangs resembled crooked Turkish scimitars, and the cave lions Pamhera spelaea. The well-known hyenas, wolves, foxes, raccoons and wolverines already lived in the glacial stage.
The Holocene epoch of the Quaternary period is the time of the formation of the modern appearance of the fauna and flora of our planet. The diversity of living organisms today is noticeably less than in past geological epochs. This may have contributed to the intense human impact on the environment. The appearance of the first great apes as early as the Tertiary period ensured their further evolution in the Quaternary period of the Cenozoic. It became possible the appearance of the ancient ancestors of modern man - Driopithecus and Australopithecus. The next stage in the evolutionary ladder is the emergence of a skilled man, the first representative of the genus Homo, and, finally, the species to which the people living now belong, Homo sapiens. From that moment, a completely new life began on the planet. 
In connection with the appearance of modern man and the development of human civilization during the Quaternary period, it was proposed to call this stage of the Cenozoic era the anthropogen. During the Holocene era, human civilization spread throughout the world. It has gradually become the most important global factor that has changed the biosphere of our planet. In particular, the emergence of agriculture has destroyed a large number of species of wild plants in order to clear crop areas and pastures. In many cases, the activities of people were ill-conceived and destructive to their environment.
Thus, the Quaternary period of the Cenozoic passed already with the participation and significant influence of man on the world around him. As the ice melted, the human civilization settled on the territories freed from under the glaciers. During this period, mastodons, mammoths, saber-toothed tigers and big-horned deer gradually became extinct. A significant role in this process was again played by ancient people who were actively engaged in hunting. They exterminated the mammoth and woolly rhinoceros in Eurasia, as well as mastodons, horses and sea cows in America. Plowing land, widespread hunting, burning forests for pastures and trampling grass stands by domestic animals have reduced the habitats of many representatives of the steppe fauna. Human activities contributed to the expansion of desert areas and the emergence of shifting sands.
The separation and movement of individual continents, as well as the establishment of climatic zonality, led to the isolation of representatives of the biosphere by region. The development of life in the Cenozoic provided the biological diversity on Earth that we can observe today. The result of the long evolution of life on our planet was the appearance of Homo sapiens at the end of the Quaternary period of the Cenozoic. With the end of prehistoric times, man began to create his own history. If about 4 thousand years ago, about 50 million people lived in the world, then already in the first half of the 19th century, the number of people on the planet exceeded one billion. It is human activity that largely predetermined the species composition of the biosphere that exists at the present time. Man also influenced the modern geographical distribution of living organisms on Earth.
The Cenozoic Ice Age (30 million years ago - present) is a recently begun ice age.
Is the present time the Holocene that has begun? 10,000 years ago, characterized as a relatively warm period after the Pleistocene ice age, often qualified as an interglacial. Ice sheets exist in the high latitudes of the northern (Greenland) and southern (Antarctica) hemispheres; at the same time, in the northern hemisphere, the Greenland ice cover extends south to 60 ° north latitude (i.e., to the latitude of St. Petersburg), fragments of the sea ice cover - to 46--43 ° north latitude (i.e. Crimea), and permafrost up to 52--47 ° north latitude. In the southern hemisphere, the continental part of Antarctica is covered by an ice sheet with a thickness of 2500–2800 m (up to 4800 m in some areas of East Antarctica), while ice shelves make up ? 10% of the area of the continent that rises above sea level. In the Cenozoic Ice Age, the Pleistocene Ice Age is the strongest: a decrease in temperature led to glaciation of the Arctic Ocean and the northern regions of the Atlantic and Pacific Ocean, while the glaciation boundary passed 1500-1700 km south of the modern one.
Geologists divide the Cenozoic into two periods: Tertiary (65 - 2 million years ago) and Quaternary (2 million years ago - our time), which in turn are divided into epochs. Of these, the first is much longer than the second, but the second - Quaternary - has a number of unique features; this is the time of the ice ages and the final formation of the modern face of the Earth.
Rice. 4
*34 million years ago - the birth of the Antarctic ice sheet
*25 million years ago -- its abbreviation
* 13 million years ago -- its re-growth
* about 3 million years ago - the beginning of the Pleistocene ice age, the repeated appearance and disappearance of ice sheets in the northern regions of the Earth
Tertiary period
The Tertiary period consists of epochs:
Paleocene
Oligocene
Pliocene
Paleocene epoch (from 65 to 55 million years ago)
Geography and climate: The Paleocene marked the beginning of the Cenozoic era. At that time, the continents were still in motion, as the "great southern continent" Gondwana continued to break apart. South America was now completely cut off from the rest of the world and turned into a kind of floating "ark" with a unique fauna of early mammals. Africa, India and Australia have moved further apart. Throughout the Paleocene, Australia was located near Antarctica. Sea levels have dropped and new landmasses have appeared in many parts of the world.
Fauna: On land, the age of mammals began. Rodents and insectivores appeared. Among them were large animals, both predatory and herbivorous. In the seas, marine reptiles have been replaced by new species of predatory bony fish and sharks. New varieties of bivalves and foraminifera emerged.
Flora: New species of flowering plants and the insects that pollinated them continued to spread.
Eocene epoch (from 55 to 38 million years ago)
Geography and climate: In the Eocene, the main land masses began to gradually assume a position close to that which they occupy today. A large part of the land was still divided into a kind of giant islands, as the huge continents continued to move away from each other. South America has lost contact with Antarctica, and India has moved closer to Asia. At the beginning of the Eocene, Antarctica and Australia were still located nearby, but later they began to diverge. North America and Europe also split apart, creating new mountain ranges. The sea flooded part of the land. The climate was generally warm or temperate. Most of it was covered with lush tropical vegetation, and vast areas were overgrown with dense swampy forests.
Fauna: Bats, lemurs, tarsiers appeared on land; the ancestors of today's elephants, horses, cows, pigs, tapirs, rhinos and deer; other large herbivores. Other mammals, such as whales and sirens, have returned to the aquatic environment. The number of species of freshwater bony fish has increased. Other groups of animals also evolved, including ants and bees, starlings and penguins, giant flightless birds, moles, camels, rabbits and voles, cats, dogs, and bears.
Flora: In many parts of the world, forests with lush vegetation grew, palm trees grew in temperate latitudes.
Oligocene epoch (from 38 to 25 million years ago)
Geography and climate: In the Oligocene era, India crossed the equator, and Australia finally separated from Antarctica. The climate on Earth became cooler, a huge ice sheet formed over the South Pole. For the formation of such a large amount of ice, no less significant volumes of sea water were required. This led to a decrease in sea levels throughout the planet and the expansion of the territory occupied by land. Widespread cooling caused the disappearance of the lush rainforests of the Eocene in many parts of the globe. Their place was taken by forests, which preferred a more temperate (cool) climate, as well as vast steppes spread over all continents.
Fauna: With the spread of the steppes, the rapid flowering of herbivorous mammals began. Among them, new species of rabbits, hares, giant sloths, rhinos and other ungulates arose. The first ruminants appeared.
Flora: Tropical forests have shrunk and begun to give way to temperate forests, and vast steppes have appeared. New herbs spread rapidly, new types of herbivores developed.
Miocene epoch (from 25 to 5 million years ago)
Geography and climate: During the Miocene, the continents were still "on the march", and during their collisions a number of grandiose cataclysms occurred. Africa "crashed" into Europe and Asia, resulting in the emergence of the Alps. When India and Asia collided, the Himalayan mountains shot up. At the same time, the Rocky Mountains and the Andes formed as other giant plates continued to shift and pile on top of each other.
However, Austria and South America still remained isolated from the rest of the world, and each of these continents continued to develop its own unique fauna and flora. The ice sheet in the southern hemisphere spread to the whole of Antarctica, which led to further cooling of the climate.
Fauna: Mammals migrated from mainland to mainland along the newly formed land bridges, which dramatically accelerated evolutionary processes. Elephants from Africa moved to Eurasia, while cats, giraffes, pigs and buffaloes moved in the opposite direction. Saber-toothed cats and monkeys appeared, including anthropoids. In Australia, cut off from the outside world, monotremes and marsupials continued to develop.
Flora: Inland regions became colder and drier, and steppes spread more and more in them.
Pliocene epoch (from 5 to 2 million years ago)
Geography and Climate: A space traveler looking down on the Earth at the beginning of the Pliocene would find the continents in almost the same places as they are today. The gaze of a galactic visitor would open up giant ice caps in the northern hemisphere and the huge ice sheet of Antarctica. Because of all this mass of ice, the climate of the Earth became even cooler, and it became much colder on the surface of the continents and oceans of our planet. Most of the forests that survived in the Miocene disappeared, giving way to vast steppes that spread all over the world.
Fauna: Herbivorous hoofed mammals continued to multiply and evolve rapidly. Toward the end of the period, a land bridge connected South and North America, which led to a grand "exchange" of animals between the two continents. It is believed that the intensified interspecific competition caused the extinction of many ancient animals. Rats entered Australia, and the first humanoid creatures appeared in Africa.
Flora: As the climate cools, steppes have replaced forests.
Fig.5
Quaternary period
Consists of epochs:
Pleistocene
Holocene
Pleistocene epoch (from 2 to 0.01 million years ago)
Geography and climate: At the beginning of the Pleistocene, most of the continents occupied the same position as today, and some of them needed to cross half the globe to do this. A narrow land "bridge" connected North and South America. Australia was located on the opposite side of the Earth from Britain. Giant ice sheets were creeping into the northern hemisphere. It was the era of the great glaciation with alternating periods of cooling and warming and fluctuations in sea level. This ice age continues to this day.
Animals: Some animals have managed to adapt to the increased cold by acquiring thick wool: for example, woolly mammoths and rhinos. Of the predators, saber-toothed cats and cave lions are the most common. This was the age of the giant marsupials in Australia and the huge flightless birds, such as the moa or epiornis, that lived in many parts of the southern hemisphere. The first people appeared, and many large mammals began to disappear from the face of the Earth.
Flora: Ice gradually crept from the poles, and coniferous forests gave way to tundra. Farther from the edge of the glaciers, deciduous forests gave way to coniferous ones. In the warmer regions of the globe, there are vast steppes.
Holocene epoch (from 0.01 million years to the present day)
Geography and climate: The Holocene began 10,000 years ago. During the entire Holocene, the continents occupied practically the same places as today, the climate was also similar to the modern one, becoming either warmer or colder every few millennia. Today we are experiencing one of the periods of warming. As the ice sheets decreased, the sea level slowly rose. The beginning of the time of the human race.
Fauna: At the beginning of the period, many species of animals became extinct, mainly due to the general warming of the climate, but, perhaps, increased human hunting for them also affected. Later, they may have fallen victim to competition from new animal species introduced by people from other places. Human civilization has become more advanced and spread all over the world.
Flora: With the advent of agriculture, the peasants destroyed more and more wild plants in order to clear areas for crops and pastures. In addition, plants brought by people to areas new to them sometimes crowded out indigenous vegetation.
Rice. 6
Ice Age Tertiary Quaternary
The time limits of the Cenozoic era are not difficult to determine: this is a period of geological time, originating from the Cretaceous-Paleogene extinction event that destroyed the dinosaurs 66 million years ago and continuing up to the present day. Informally, the Cenozoic era is often referred to as the "age of mammals" because it was only after the dinosaurs became extinct that mammals were able to fill the vacated ecological niches and become the dominant land life on the planet.
However, this characterization is somewhat unfair, since not only mammals flourished during the Cenozoic, but also reptiles, birds, fish, and even invertebrates!
Somewhat confusingly, the Cenozoic era is divided into various "periods" and "eras", and scientists do not always use the same terminology when describing their research or discoveries. (This situation contrasts sharply with the preceding Mesozoic era, which is more or less neatly divided into , and periods.)
In the case of the Cenozoic era, the following main periods and eras are distinguished:
Paleogene period
(66-23 million years ago) was the time when mammals began their dominance. The Paleogene consists of three distinct epochs:
Paleocene epoch
The Paleocene epoch, or Paleocene (66-56 million years ago) was quite calm from an evolutionary point of view.
During this time, the tiny mammalian survivors tasted their newfound freedom for the first time and began cautiously exploring new ecological niches. During the Paleocene era, large snakes, crocodiles and turtles were abundant.
Eocene epoch
The Eocene epoch, or Eocene (56-34 million years ago) was the longest epoch of the Cenozoic era.
In the Eocene there was an enormous abundance of mammalian species; at this time, the first four-legged ungulates appeared on the planet, as well as the first recognizable primates.
Oligocene epoch
The Oligocene epoch, or Oligocene (34-23 million years ago), differs in climate change from the previous Eocene, which opened up even more ecological niches for mammals. This was the era when some mammals (and even some birds) began to develop to gigantic sizes.
Neogene period
(23-2.6 million years ago) was marked by the ongoing evolution of mammals and other life forms, many of which were huge. The Neogene consists of two epochs:
Miocene epoch
The Miocene epoch, or Miocene (23-5 million years ago) occupies the lion's share of the Neogene. Most of the mammals, birds and other animals began to take on an appearance close to modern, although they were much larger.
Pliocene Epoch
The Pliocene epoch, or Pliocene (5-2.6 million years ago), is often confused with the subsequent Pleistocene. This was the time when many mammals migrated (often via land bridges) to the territories they continue to inhabit today. Horses, primates, and other animal species continued to evolve.
Quaternary period
(2.6 million years ago - to the present) is still the shortest of all the geological periods of the Earth. The Anthropogene consists of two even shorter epochs:
Pleistocene Epoch
The Pleistocene epoch, or Pleistocene (2.6 million - 12 thousand years ago), is characterized by large megafauna mammals, such as woolly and which died out at the end of the last ice age (partly due to climate change and predation by the earliest people).
Holocene epoch
The Holocene epoch, or Holocene (12,000 years ago - to the present day) represents almost the entire modern history of mankind. Unfortunately, this is also an era when many mammals and other life forms became extinct due to environmental changes caused by negative anthropogenic impacts from human activities.
Quaternary (Anthropogenic)
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Quaternary (Anthropogenic) originates 2.6 million liters. n. and continues to this day. During this time period, three main things happened:
- the planet entered a new ice age, during which sharp cooling alternated with warming;
- the continents took their final current outlines, a modern relief was formed;
- a reasonable man appeared on the planet.
Subsections of the anthropogen, geological changes, climate
Almost the entire length of the Anthropogen is occupied by the Pleistocene department, which, according to international standards of stratigraphy, is usually divided into the Gelaz, Calabrian, Middle and Upper stages, and the Holocene, which originates a little more than 11 thousand years ago. n. and continues to this day.
Basically, the continents in their present form were formed long before the beginning of the Quaternary period, but it was during this period of time that many young mountain ranges acquired their present form. The coastline of the continents took on its current shape, and due to the alternately advancing and retreating glaciers, the extreme northern continental archipelagos, such as the Canadian, Svalbard, Iceland, Novaya Zemlya, etc., were formed. 100 meters.
Retreating, the giant Anthropogene glaciers left behind a trail of deep moraines. During the periods of maximum glaciation, the total area of glaciers exceeded the current one by more than three times. Thus, it can be said that large parts of North America, Europe and present-day Russia were buried under ice layers.
It is worth saying that the current ice age in the history of the earth is not the first. For several billion years, the first historical ice age lasted, originating 1.5 billion years ago. n. in the early Proterozoic. After prolonged heat, a 270-million-year cooling hit the planet again. It happened 900 million liters. n. in the Late Proterozoic. Then another significant icing took place, which lasted for 230 million years. n. in the Paleozoic (460 - 230 million years ago). And now the planet is experiencing another cooling, the beginning of which is usually attributed to 65 million years ago. It gradually gained strength and it is not yet known whether the Cenozoic global ice age has survived its apogee of low temperatures.
Rice. 1 - Anthropogene (Quaternary period)
During the current ice age, a great many warming and cooling events have occurred, and according to scientists, in this period of time, the Earth is experiencing a warming stage. According to their calculations, the last cooling was replaced by warming from 15 to 10 thousand years ago. During the strongest Pleistocene glaciations, the line of glaciers descended from 1500 to 1700 km south of the current line.
Anthropogenic climate was subject to frequent fluctuations. In those times when glaciers advanced, the climatic zones narrowed and retreated closer to the equator, and, conversely, during periods of warming and massive melting of glaciers, the temperate zone extended to the northernmost continental margins and, as a result, the rest of the climatic zones also expanded.
Quaternary sedimentation
On the Quaternary sedimentation left its mark on the rapid variability of lithological components and genesis. Sediments in the Quaternary period accumulated everywhere, but due to the complex structure of the sections, it is rather difficult to distinguish them. The rate of accumulation of anthropogenic deposits was too high, but due to the lack of pressure, the deposits still have a rather loose structure. The conditions of occurrence are also atypical. If sequential stratification is considered typical, then the term “leaning” against lower and older deposits is more appropriate here. Continental zones are more typical of continental deposits, such as glacial, water and eolian. For the seas, volcanic, organogenic, trigenic and chemogenic sediments are more typical.
Quaternary Animals
Among the invertebrates in the Pleistocene of the Quaternary period, all kinds of snails and other land molluscs developed unusually. The underwater world was in many respects similar to the previous Neogene. The world of insects also began to acquire similarities with the present, but the world of mammals was subject to the most interesting metamorphoses.
Since the beginning of the Anthropogen, elephant-like varieties have become widespread. At the beginning of the Pleistocene, they inhabited vast territories of the Eurasian continent. Some of their species reached a height of 4 m at the withers. Increasingly, species of elephants covered with long hair began to appear in the northern parts of the continents. By the middle of the Pleistocene, mammoths were already the most common and most common representatives of the northern tundra latitudes. Having migrated over the ice of the Bering Strait in one of the next periods of cooling to Alaska, mammoths also bred throughout the entire North American continent. It is believed that mammoths originated from trogontherian elephants, on the border of the Neogene and Pleistocene, widespread in the steppe latitudes.
In the southern latitudes of both North America and Eurasia, other elephant species were widely distributed. Among others, giant mastodons stood out. Tellingly, these representatives of elephants on the territory of the Eurasian continent completely died out by the end of the Pleistocene, while on the American continent they successfully survived all stages of the Earth's glaciation.
Rhinos also stood out among other giants of the Quaternary period. Their woolly varieties inhabited the tundra-steppes of the early and middle anthropogen along with mammoths.
were numerous quaternary animals from the category of horses. Tellingly, the ancient descendant of horses was from the North American part of Pangea. After the split of the mainland and the cessation of animal migration between the American and Eurasian segments, equines completely died out on the North American mainland, and only those species that managed to migrate to the Eurasian continent evolved. Subsequently, they reappeared in America only thanks to man.
Along with horses, which inhabited the European-Asian savannahs in large numbers, hippos were also active during periods of anthropogenic warming. In large numbers, their remains were found on the islands of Great Britain. Various artiodactyl varieties of deer were also numerous, the most common of which was the Irish bighorn. In the span of his horns sometimes reached up to 3 meters.
In the Quaternary period, the first goats appeared, among which the mountain varieties were the most numerous. The first tours appeared, the progenitors of domestic bulls. Huge pastures of all kinds of roe deer, bison, musk oxen grazed on the steppe expanses; to the south, the first varieties of camels appeared.
Also, along with herbivores, a detachment of predators also developed. For example, a variety of bears could be found both in the snowy areas of the northern latitudes and in the tundra forests. Many of them also lived to the south, descending to the steppe zone of temperate latitudes. Many of them, who inhabited the caves of the glacial Pleistocene, could not survive in the cold conditions of the Arctic at that time, but, one way or another, many of their varieties have successfully survived to this day.
Numerous were in the northern regions such deadly anthropogen predators(Fig. 2), like saber-toothed tigers, and cave lions, which were much more massive and larger and more dangerous than their modern relatives. Often, these dangerous predators became the themes of the art of ancient rock artists.
Rice. 2 - Predators of the Quaternary period
Also among others fauna of the Quaternary period other diverse species were also represented, such as hyenas, wolves, foxes, raccoons, wolverines, etc. There were also a large number of rodents in the form of lemmings, ground squirrels, beavers of various varieties, up to the giant Trognotherium cuvieri.
The kingdom of birds was also very diverse, among which both flying and flightless varieties stood out.
By the end of the Pleistocene, many varieties of mammals that previously inhabited the tundra-steppes died out. To such mammals of the Quaternary period can be attributed:
- on the territory of South America - the armadillo teticurus, the giant saber-toothed cat smilodon, hoofed macrouchenia, sloths megatherium, etc .;
- on the territory of North America - the last representatives of tyrant birds or fororakos - Waller's titanis, many representatives of ungulates, such as American horses, camels, steppe peccaries, deer, bulls and pronghorn antelopes;
- on the territory of the tundra-steppes of Eurasia, Alaska and Canada - mammoths, woolly rhinos, bighorn deer, cave lions and bears.
In the Holocene, such flightless bird species as dodos and epiornis died out, and the giant seal-like Stellarian cow disappeared from the depths of the sea.
Anthropogenic plants
The climate of the Pleistocene, with constant alternations of glacial and interglacial intervals, had an adverse effect on anthropogenic plants growing in northern continental latitudes. With the onset of cold snaps, the climatic life barrier was sometimes forced to shift to the line of 40 ° N. sh., and in some places even lower. Over the past two million years, vegetation has been forced to alternately retreat to the above latitudes, then grow again up to the shores of the Arctic Ocean. As a result of a cold snap, many heat-loving plants that had been in their genus since the Triassic were doomed to extinction. With the disappearance of many varieties of grasses, shrubs and other plants, the extinction of many species of Anthropogene animals is also associated. Therefore, it is not worth placing all the blame for the disappearance of such species as the same mammoth entirely on the shoulders of ancient people.
In the glacial epochs of the Quaternary, to the south of the tip of the glaciers, three belts of vegetation began to exist - tundra, steppe and taiga. The tundra was covered with mosses and lichens; to the south, dwarf birches, polar willows, and alpine silverworts began to grow. The tundra was also characterized by azaleas, saxifers, saplings, etc. The steppe zone was full of all kinds of herbs and low shrubs. But closer to the south, in some places, there were also woodlands, consisting of willow and birch forests. The taiga forests of the Anthropogen were mainly composed of pines and spruces, which mixed closer to the south with birches, aspens and other deciduous deciduous trees.
During the interglacial epochs, the composition of the flora of the Quaternary period changed significantly. Pushed aside to the south by glaciers, thickets of such flowering and shrubs as lilies, rhododendrons and roses returned to their places. But little by little, towards the approach of the Holocene, the interglacial vegetation became more and more sparse due to constant forced migrations. Many walnut and yew trees, which previously formed huge forest tracts, have now become rare. In the warmest interglacial periods, the Central European territory was completely covered with broad-leaved forests consisting of oak, beeches, lindens, maples, hornbeam, ash, hawthorn and some walnuts.
In places where interglacial plant migrations were not impeded by mountain ranges and seas, specimens of the ancient vegetation of the Triassic period were still preserved. For example, in North America, where migrations were not impeded, as in the case of the mountain ranges of Europe, as well as the Mediterranean Sea, magnolias, lilyodendrons, taxodiums and Weymouth pines (Pinus strobus) still grow in some areas.
Far to the south, the vegetation did not undergo any definite differences from the previous Neogene period.
The ancestors of today's people appeared at the end of the Neogene 5 million years ago. n. They were descended from one of the branches of hominids australopithecines, and their remains were found only on the African continent, which gives reason to say that the ancestral home of all mankind is Africa. The warm climate and rough vegetation of these places contributed to the increasing evolutionary development of Australopithecus, until, finally, the first of them at the turn of the Quaternary period mastered primitive types of tools. The next branch of the development of a skilled man (Homo habilis) was archanthropes, the direct ancestors of modern people, who in the second half of the Pleistocene actively began to settle on all continents. One of the most famous offshoots of the archanthropes are pithecanthropes, the remains of which archaeologists find almost everywhere. In the region of 400-350 thousand liters. n. the first transitional forms of ancient people from archanthropes to paleoanthropes began to appear, which include Neanderthals, which subsequently died out, unable to withstand competition from Cro-Magnons. Although, according to some scientists, these two species simply mixed with each other. Further, paleoanthropes developed into neoanthropes, who already differed little from modern people. It happened in the region of 40-35 thousand liters. n. In particular, the Cro-Magnons were the first representatives of the neoanthropes.
Rice. 3 - The formation of man during the Anthropogen period
Gradually, people mastered more and more complex tools. 13 thousand liters n. bow and arrows appeared, after that people learned how to burn pots and acquired the first items made of ceramics. They started farming and cattle breeding. 5 thousand liters n. the first products made of bronze and copper appeared, and somewhere between 3 and 2.5 thousand years ago. n. the age of iron began.
Since that time, the improvement of tools has gone much faster, in the Middle Ages, the development of science and technology began, which have now reached a level that allowed people to develop such sciences as genetics and genetic engineering.
Minerals of the Quaternary period
Quaternary deposits contain many different minerals. Alluvial deposits within mountain ranges and zones of tectonic activity are rich in gold, diamonds, cassiterite, ilmenite, etc. Deposits that form in humid tropical zones and are weathering crusts contain reserves of bauxite, manganese and nickel, as well as such non-metallic building materials as loams, clays, gravel, sandstone, limestone. There are also numerous accumulations of brown coals, deposits of natural gas, diatomites, salts, bean iron ores, sapropels, etc. Also in volcanic areas, deposits of sulfur and manganese can be found. Peat sedimentary accumulations are numerous and ubiquitous.
The layers of the Quaternary period contain a huge amount of fresh groundwater, some thermal springs originate in their depths, and various therapeutic muds formed in the Anthropogen are also intensively used in our time.
“General biology. Grade 11". V.B. Zakharov and others (gdz
Question 1. Describe the evolution of life in the Cenozoic era.
In the Quaternary period of the Cenozoic era, cold-resistant grass and shrub vegetation appears, in large areas the forests are replaced by steppe, semi-desert and desert. Modern plant communities are being formed.
The development of the animal world in the Cenozoic era is characterized by further differentiation of insects, intensive speciation in birds, and extremely rapid progressive development of mammals.
Mammals are represented by three subclasses: monotremes (platypus and echidna), marsupials and placentals. Monotremes originated independently of other mammals back in the Jurassic period from animal-like reptiles. Marsupials and placental mammals evolved from a common ancestor in the Cretaceous and coexisted until the onset of the Cenozoic era, when there was an "explosion" in the evolution of placental mammals, as a result of which placental mammals displaced marsupials from most continents.
The most primitive were insectivorous mammals, from which the first carnivores and primates descended. Ancient carnivores gave rise to ungulates. By the end of the Neogene and Paleogene, all modern families of mammals are already found. One of the groups of monkeys - Australopithecus - gave rise to a branch leading to the genus man.
Question 2. What impact did extensive glaciation have on the development of plants and animals in the Cenozoic?
In the Quaternary period of the Cenozoic era (2-3 million years ago), glaciation of a significant part of the Earth began. Heat-loving vegetation recedes to the south or dies out, cold-resistant grass and shrub vegetation appears, in large areas forests are replaced by steppe, semi-desert and desert. Modern plant communities are being formed.
Mammoths, woolly rhinos, reindeer, arctic foxes, polar partridges were found in the North Caucasus and Crimea.
Question 3. How can you explain the similarities between the fauna and flora of Eurasia and North America?
The formation of large masses of ice during the glaciation of the Quaternary period caused a decrease in the level of the World Ocean. This decrease was 85-120 m compared to the current level. As a result, the continental shoals of North America and Northern Eurasia were exposed and land "bridges" appeared connecting the North American and Eurasian continents (in the place of the Bering Strait). On such "bridges" the migration of species occurred, which led to the formation of the modern fauna of the continents.
Paleogene
In the Paleogene, the climate was warm and humid, as a result of which tropical and subtropical plants became widespread. Representatives of the marsupial subclass were widespread here.
Neogene
see Hipparion fauna
By the beginning of the Neogene, the climate became dry and temperate, and by the end of it, a sharp cooling began.
These climate changes led to the reduction of forests, the emergence and wide distribution of herbaceous plants.
The class of insects developed intensively. Among them, highly organized species arose that contributed to the cross-pollination of flowering plants and fed on plant nectar.
The number of reptiles has decreased. Birds and mammals lived on land and in the air, fish lived in the water, as well as mammals that re-adapted to life in the water. During the Neogene period, many genera of currently known birds appeared.
At the end of the Neogene, marsupials gave way to placental mammals in the struggle for existence. The oldest of the placental mammals are representatives of the order of insectivores, from which other orders of placental animals, including primates, originated during the Neogene.
In the middle of the Neogene, apes developed.
Due to the reduction of forests, some of them were forced to live in open areas. Subsequently, primitive people descended from them. They were not numerous and constantly struggled with natural disasters, defended themselves from large predatory animals.
Quaternary (Anthropogenic)
great glaciation
great glaciation
In the Quaternary period, there was a repeated shift of the ice of the Arctic Ocean to the south and back, which was accompanied by cooling and the movement of many heat-loving plants to the south.
With the retreat of the ice, they moved to their former places.
29. Development of life in the Cenozoic era.
Such repeated migration (from Latin migratio - relocation) of plants led to the mixing of populations, the extinction of species that were not adapted to the changed conditions, and contributed to the emergence of other, adapted species.
human evolution
see Human evolution Material from the site http://wikiwhat.ru
By the beginning of the Quaternary period, the evolution of man is accelerating. The methods of manufacturing tools and their use are being significantly improved. People begin to change the environment, learn to create favorable conditions for themselves.
The increase in the number and wide distribution of people began to influence the flora and fauna. Hunting by primitive people leads to a gradual reduction in the number of wild herbivores. The extermination of large herbivores has led to a sharp decrease in the number of cave lions, bears and other large predatory animals that feed on them.
Trees were cut down and many forests turned into pastures.
On this page, material on the topics:
Cenozoic era brief description
Cenozoic era third period climate
Cambrian briefly
Rjqyjpjq
Neogene in a nutshell
Questions for this article:
Name the periods of the Cenozoic era.
What changes occurred in the plant and animal world in the Cenozoic era?
In what period did the main orders of mammals appear?
Name the period in which the great apes developed.
Material from the site http://WikiWhat.ru
CENOSIOIC ERATEM (ERA), Cenozoic (from the Greek kainos - new and zoe - life * a. Cainozoic, Cenozoic, Kainozoic era; n. Kanozoikum, kanonisches Arathem; f. erateme cenozoique; and. eratema cenozoiso), - the uppermost ( young) erathema (group) of the general stratigraphic scale of the layers of the earth's crust and the latest era of the geological history of the Earth corresponding to it.
It began 67 million years ago and continues to this day. The name was proposed by the English geologist J. Phillips in 1861. It is divided into the Paleogene, Neogene and Quaternary (Anthropogenic) systems (periods). The first two until 1960 were combined into a tertiary system (period).
general characteristics. By the beginning of the Cenozoic, there were the Pacific and Mediterranean geosynclinal belts, within which thick strata of geosynclinal sediments accumulated in the Paleogene and almost throughout the entire Neogene.
The modern distribution of continents and oceans is taking shape. The disintegration of the previously unified southern continental massif of Gondwana, which took place during the Mesozoic era, is coming to an end. By the beginning of the Cenozoic, two large platform continents stood out in the Northern Hemisphere of the Earth - Eurasian and North American, separated by the not yet fully formed northern basin of the Atlantic Ocean.
By the middle of the Cenozoic era, Eurasia and Africa formed the continental massif of the Old World, soldered by mountain structures of the Mediterranean geosynclinal belt. In the Paleogene, the site of the latter was occupied by the vast Tethys marine basin that had existed since the Mesozoic, stretching from Gibraltar to the Himalayas and Indonesia.
In the middle of the Paleogene, the sea penetrated from the Tethys and to neighboring platforms, flooding vast areas within modern Western Europe, the south of the European part of the CCCP, Western Siberia, Central Asia, North Africa and Arabia. Starting from the Late Paleogene, these territories gradually freed themselves from the sea.
In the Mediterranean belt, as a result of Alpine tectogenesis, by the end of the Neogene, a system of young folded mountains was formed, including the Atlas, Andalusian Mountains, Pyrenees, Alps, Apennines, Dinaric Mountains, Stara Planina, Carpathians, Caucasus, Hindu Kush, Pamir, Himalayas, mountains of Asia Minor, Iran , Burma and Indonesia.
Tethys began to gradually break up into parts, the long evolution of which led to the formation of a system of depressions of the Mediterranean, Black and Caspian Seas. The Pacific geosynclinal belt in the Paleogene (as well as in the Neogene) consisted of several geosynclinal regions stretching for thousands of kilometers along the periphery of the Pacific Ocean floor.
The largest geosynclines: East Asian, New Guinea-New Zealand (encircles Australia from the east), Andean and California. The thickness of terrigenous (clays, sands, diatomites) and volcanogenic (andesite-basalts, rare-acid volcanic rocks and their tuffs) strata in them reaches 14 km. Denudation dominated in the area of mesozoid development (Verkhoyansk-Chukotka and Cordillera folded regions), highly elevated in the Paleogene. Sediments accumulated only in graben-like depressions (coal-bearing strata of small thickness).
From the middle of the Miocene, the Verkhoyansk-Chukotka region experienced epiplatform orogeny with a range of movements (Verkhoyansky, Chersky and other ranges) of 3-4 km.
The area of the Bering Sea dried up, connecting Asia and North America.
In North America, uplifts were sometimes accompanied by massive outpourings of lavas. The bloc movements captured here the outskirts of the adjacent ancient North American (Canadian) platform, creating a chain of blocky Rocky Mountains parallel to the Cordillera.
The development of life in the Cenozoic era and its current stage
In Eurasia, arched uplifts and block displacements along faults covered even larger areas of folded structures of various ages, causing the formation of mountainous relief in spaces that had previously been strongly leveled by long-term denudation (Tien Shan, Altai, Sayans, Yablonovy and Stanovoy Ranges, mountains of Central Asia and Tibet , the Scandinavian Peninsula and the Urals).
Along with this, long-range fault systems are formed, accompanied by linearly elongated rifts, expressed in the relief in the form of deep valley-like depressions, in which large reservoirs are often located (the East African rift system, the Baikal rift system).
Within the folded epipaleozoic Atlantic folded geosynclinal belt, the depression of the Atlantic Ocean developed and took shape.
The Quaternary period is a typical theocratic era. The land area increased significantly by the end of the Neogene. By the beginning of the Quaternary period, two geosynclinal belts remained on the surface of the Earth - the Pacific and the Mediterranean. In the Early Quaternary, in connection with a major regression, Europe and North America united through Iceland, Asia - with Alaska, Europe - with Africa. The Aegean Sea, the Dardanelles, the Bosporus did not yet exist; in their place was land, connecting Europe with Asia Minor.
During the Quaternary period, the seas repeatedly changed their outlines. Anteclises and syneclises, which have existed since the Paleozoic, continue to develop on the platforms. Folded mountain structures still rise in the mountain belts (the Alps, the Balkans, the Carpathians, the Caucasus, the Pamirs, the Himalayas, the Western Cordillera, the Andes, and others), and the intermountain and foothill depressions are filled with molasses.
Volcanic eruptions are associated with young faults.
The climate of the Earth during the Paleogene was much warmer than today, but it was characterized by multiple fluctuations with a general trend towards relative cooling (from the Paleogene to the Quaternary period).
Even within the Arctic, mixed forests grew, and much of Europe, northern Asia, and North America had tropical and subtropical vegetation. Extensive uplifts of the continents in the 2nd half of the Cenozoic era caused the drainage of a significant part of the shelf of Northern Eurasia and North America. The contrasts between climatic zones increased, a general cooling set in, accompanied by powerful continental glaciations in Europe, Asia and North America.
In the Southern Hemisphere, the glaciers of the Andes and New Zealand have increased dramatically in size; Tasmania was also subjected to glaciation. Glaciation of Antarctica began at the end of the Paleogene, and in the Northern Hemisphere (Iceland) - from the end of the Neogene. The recurrence of Quaternary glacial and interglacial epochs caused rhythmic changes in all natural processes in the Northern Hemisphere, incl. and in sedimentation. The last ice sheet in North America and Europe disappeared 10-12 thousand years ago, see Fig.
Quaternary system (period). In the modern era, 94% of the volume of ice is concentrated in the southern hemisphere of the Earth. In the Quaternary period, under the influence of tectonic (endogenous) and exogenous processes, the modern relief of the Earth's surface and the bottom of the oceans was formed. In general, the Cenozoic era is characterized by repeated changes in the level of the World Ocean.
organic world. At the turn of the Mesozoic and Cenozoic, the groups of reptiles that dominated the Mesozoic die out and their place in the terrestrial animal world is occupied by mammals, which, together with birds, make up most of the terrestrial vertebrates of the Cenozoic era. On the continents, higher placental mammals predominate, and only in Australia does a peculiar fauna of marsupials and partly monotremes develop.
From the middle of the Paleogene, almost all existing orders appear. Part of the mammals for the second time passes to living in the aquatic environment (cetaceans, pinnipeds). From the beginning of the Cenozoic era, a detachment of primates appeared, the long evolution of which led to the appearance in the Neogene of higher anthropoid apes, and at the beginning of the Quaternary period, the first primitive people.
The invertebrate fauna of the Cenozoic era differs less sharply from that of the Mesozoic. Ammonites and belemnites are completely dying out, bivalves and gastropods, sea urchins, six-ray corals, etc. dominate. Nummulites (large foraminifera) develop rapidly, making up thick limestone strata in the Paleogene. In terrestrial vegetation, angiosperms (flowering plants) continued to dominate. Starting from the middle of the Paleogene, herbaceous formations of the savanna and steppe type appear, from the end of the Neogene, formations of coniferous forests of the taiga type, and then forest-tundra and tundra.
Minerals. Approximately 25% of all known oil and gas reserves are confined to Cenozoic deposits, the deposits of which are concentrated mainly in marginal troughs and intermountain depressions framing alpine folded structures.
In the USSR, these include the fields of the Pre-Carpathian oil and gas region, the North Caucasian-Mangyshlak oil and gas province, the South Caspian oil and gas province, and the Ferghana oil and gas region. Significant oil and gas reserves are concentrated in oil and gas basins: Great Britain (North Sea oil and gas region), Iraq (Kirkuk field), Iran (Gechsaran, Marun, Ahvaz, etc.), USA (California oil and gas basins), Venezuela (Maracaib oil and gas basin), Egypt and Libya (Sahara-Libyan oil and gas basin), Southeast Asia.
About 15% of coal reserves (mainly brown) are associated with the deposits of the Cenozoic era. Significant reserves of brown coal of the Cenozoic era are concentrated in Europe (CCCP - Transcarpathia, Carpathians, Transnistria, Dnieper coal basin; East Germany, Germany, Romania, Bulgaria, Italy, Spain), in Asia (CCCP - South Urals, Caucasus, Lena coal basin, island Sakhalin, Kamchatka, etc.; Turkey - Anatolian lignite basin; Afghanistan, India, Nepal, countries of the Indochinese Peninsula, China, Korea, Japan, Indonesia), North America (Canada - Alberta and Saskatchewan basins; USA - Green River, Mississippi, Texas), in South America (Colombia - Antioquia basins, etc.; Bolivia, Argentina, Brazil - Alta Amazonas basins).
In Australia (Victoria), the coal-bearing Paleogene is characterized by coal accumulation unique for the entire globe - the total thickness of adjacent seams is 100-165 m, and at their confluence 310-340 m (Latrobe Valley basin).
Sedimentary strata of the Cenozoic also contain large deposits of oolitic iron ores (Kerch iron ore basin), manganese ores (Chiatursky deposit, Nikopol manganese ore basin), rock and potassium salts in the CCCP (Carpathian potassium-bearing basin), Italy (Sicily), France (Alsace), Romania , Iran, Israel, Jordan and other countries.
Large reserves of bauxites (Mediterranean bauxite-bearing province), phosphorites (Arabian-African phosphorite-bearing province), diatomites, and various non-metallic building materials are associated with the Cenozoic strata.
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Essay on the Cenozoic era.
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| Geological history of the earth in the Cenozoic era
Cenozoic era is divided into three periods: Paleogene, Neogene and Quaternary. The geological history of the Quaternary period has distinctive features inherent only to it, therefore it is considered separately. Paleogene and Neogene periods For a long time, the Paleogene and Neogene periods were united under a single name - the Tertiary period. Starting from 1960 they are considered as separate periods. The deposits of these periods constitute the corresponding systems, which have their own names. Three divisions are distinguished within the Paleogene: Paleocene, Eocene and Oligocene; within the Neogene - two: Miocene and Pliocene. These departments correspond to epochs with the same names. organic world The organic world of the Paleogene and Neogene periods differs significantly from the Mesozoic. Extinct or decayed Mesozoic animals and plants were replaced by new ones - Cenozoic. New families and genera of bivalves and gastropods, bony fishes and mammals begin to develop in the seas; on land - mammals and birds. Among terrestrial plants, the rapid development of angiosperms continues. The structure of the earth's crust and paleogeography at the beginning of the era At the beginning of the Cenozoic era, the structure of the earth's crust was quite complex and in many ways close to modern. Along with the ancient platforms, there were young ones that occupied vast areas inside geosynclinal folded belts. The geosynclinal regime has been preserved in large areas of the Mediterranean and Pacific belts. Compared with the beginning of the Mesozoic era, the areas of geosynclinal regions were greatly reduced in the Pacific belt, where by the beginning of the Cenozoic vast Mesozoic mountainous folded regions arose. There were all oceanic depressions, the outlines of which were somewhat different from modern ones. In the northern hemisphere, there were two huge platform arrays - Eurasia and North America, which consisted of ancient and young platforms. They were separated by a depression in the Atlantic Ocean, but connected in the region of the modern Bering Sea. In the south, the mainland of Gondwana no longer existed as a single entity. Australia and Antarctica were separate continents, and the connection between Africa and South America continued until the middle of the Eocene era. Quaternary period The Quaternary period is very different from all earlier ones. Its main features are the following: 1. An exceptionally short duration, which is estimated differently by various researchers: from 600 thousand to 2 million years. However, the history of this short geological period is so full of geological events of exceptional importance that it has long been considered separately and is the subject of a special science - Quaternary geology. The most important event in the history of the period is the emergence and development of man, human society and its culture. The study of the stages of development of fossil man helped to develop stratigraphy and clarify the paleogeographic setting. Back in 1922, Academician A.P. Pavlov proposed to replace the outdated name "Quaternary period" (the previously existing names "primary", "secondary" and "tertiary" periods were eliminated) with a more correct one - "anthropogenic period". 3. An important feature of the period is the giant continental glaciation caused by a strong cooling of the climate. During the maximum glaciation, more than 27% of the area of the continents was covered with ice, i.e., almost three times more than at present. The scope and boundaries of the Quaternary system are still the subject of debate. Although the decision on the duration of the Quaternary period of 700 thousand years remains in force, there are new convincing data in favor of lowering the boundary to the level of 1.8 - 2 million years. These data are associated primarily with new discoveries of the ancestors of the most ancient people in Africa. The division of the Quaternary system into Lower Quaternary, Middle Quaternary, Upper Quaternary and modern deposits is accepted. These four subdivisions are used without adding any names (department, stage, etc.) and are subdivided into glacial and interglacial horizons. The division of the Quaternary system in Western Europe is based on the horizons identified in the Alps. organic world The flora and fauna of the beginning of the Quaternary period differed little from the modern one. Development of life in the Cenozoic eraDuring the period, there was a wide migration of fauna and flora in the northern hemisphere in connection with glaciations, and during the maximum glaciation, many heat-loving forms died out. The most noticeable changes have occurred among the mammals of the northern hemisphere. To the south of the glacier borders, along with deer, wolves, foxes and brown bears, cold-loving animals lived: woolly rhinoceros, mammoth, reindeer, ptarmigan. Heat-loving animals died out: giant rhinos, ancient elephants, cave lions and bears. In the south of Ukraine, in particular in the Crimea, mammoth, ptarmigan, arctic fox, white hare, and reindeer appeared. Mammoths penetrated far to the south of Europe to Spain and Italy. The most important event that distinguishes the Quaternary period from all others is the emergence and development of man. At the turn of the Neogene and Quaternary periods, the most ancient people appeared - archanthropes. Ancient people - paleoanthropes, which include Neanderthals, were the predecessors of modern people. They lived in caves, widely used not only stone, but also bone tools. Paleoanthropes appeared in the Middle Quaternary. New people - neoanthropes - appeared in the post-glacial period, their representatives were first Cro-Magnons, and then modern man appeared. All new people are descended from the same ancestor. All races of modern man are biologically equivalent. Further changes that a person underwent depended on social factors. Quaternary glaciations Extensive glaciation has engulfed the northern hemisphere since the beginning of the Quaternary. A thick layer of ice (in some places up to 2 km thick) covered the Baltic and Canadian shields, and from here the ice sheets descended to the south. To the south of the area of continuous glaciation, there were regions of mountain glaciation. When studying glacial deposits, it turned out that the Quaternary glaciation was a very complex phenomenon in the history of the Earth. Epochs of glaciation alternated with interglacial epochs of warming. The glacier either advanced or retreated far to the north; sometimes glaciers may have disappeared almost entirely. Most researchers believe that there were at least three Quaternary ice ages in the northern hemisphere. The glaciation of Europe has been well studied; its centers were the Scandinavian mountains and the Alps. Moraines of three glaciations have been traced on the East European Plain: Early Quaternary - Oka, Middle Quaternary - Dnieper, and Late Quaternary - Valdai. During the maximum glaciation, there were two large glacial tongues that reached the latitudes of Dnepropetrovsk and Volgograd. In the west, this glacier covered the British Isles and descended south of London, Berlin and Warsaw. In the east, the glacier covered the Timan Ridge and merged with another vast glacier advancing from Novaya Zemlya and the Polar Urals. The territory of Asia has undergone a smaller area of glaciation than Europe. Extensive areas were covered here by mountain and underground glaciation. State Institution of Education "Gymnasium of Chechersk" abstract Cenozoic era Made by Asipenko Kristina, student of 11 "B" class Checked by Tatyana Potapenko Mikhailovna Chechersk, 2012 |
Cenozoic era
The Cenozoic era is the current era that began 66 million years ago, immediately after the Mesozoic era. Specifically, it originates on the border of the Cretaceous and Paleogene, when the second largest catastrophic extinction of species occurred on Earth. The Cenozoic era is significant for the development of mammals that replaced dinosaurs and other reptiles, which almost completely died out at the turn of these eras.
In the process of development of mammals, a genus of primates stood out, from which, according to Darwin's theory, humans later arose. "Cenozoic" is translated from Greek as "New Life".
Geography and climate of the Cenozoic period
During the Cenozoic era, the geographic outlines of the continents acquired the form that exists today.
The North American continent moved further and further away from the remaining Laurasian, and now the Eurasian part of the global northern continent, and the South American segment moved further and further away from the African segment of southern Gondwana. Australia and Antarctica retreated more and more to the south, while the Indian segment was more and more “squeezed out” to the north, until, finally, it joined the South Asian part of the future Eurasia, causing the rise of the Caucasian mainland, and also largely contributing to the rise from water and the rest of the current part of the European continent.
The climate of the Cenozoic era gradually became more severe.
The cooling was not absolutely sharp, but still not all groups of animal and plant species had time to get used to it. It was during the Cenozoic that the upper and southern ice caps were formed in the region of the poles, and the climatic map of the earth acquired the zonation that we have today.
It is a pronounced equatorial belt along the earth's equator, and further in order of distance to the poles - subequatorial, tropical, subtropical, temperate, and beyond the polar circles, respectively, the arctic and antarctic climatic zones.
Let's take a closer look at the periods of the Cenozoic era.
Paleogene
Throughout almost the entire Paleogene period of the Cenozoic era, the climate was warm and humid, although a constant trend towards cooling was traced throughout it.
The average temperature in the North Sea area was kept within 22-26°C. But by the end of the Paleogene, it began to get colder and sharper, and at the turn of the Neogene, the northern and southern ice caps were already formed. And if in the case of the northern sea these were separate areas of alternately formed and melting wandering ice, then in the case of Antarctica, a persistent ice sheet began to form here, which still exists today.
The average annual temperature in the region of the current polar circles has dropped to 5°C.
But until the first frosts hit the poles, renewed life both in the sea and ocean depths and on the continents flourished. Due to the extinction of dinosaurs, mammals completely populated all continental spaces.
During the first two Paleogene divisions, mammals diverged and evolved into many different forms.
Many different proboscis animals arose, indicothere (rhino), tapir and pig-like. Most of them were chained to some kind of water bodies, but many species of rodents also appeared, which also felt excellent in the depths of the continents. Some of them gave rise to the first ancestors of horses and other one and artiodactyls. The first predators (creodonts) began to appear. New species of birds arose, and vast areas of the savannas were inhabited by diatryms - a variety of flightless bird varieties.
Insects multiplied unusually.
In the seas, cephalopods and bivalve molluscs multiplied everywhere. Corals grew very strongly, new varieties of crustaceans appeared, but bony fish received the greatest flourishing.
The most widespread in the Paleogene were such plants of the Cenozoic era as tree-like ferns, various sandalwood, banana and breadfruit trees.
Closer to the equator, chestnut, laurel, oak, sequoia, araucaria, cypress, and myrtle trees grew. In the first period of the Cenozoic, dense vegetation was also widespread far beyond the polar circles. These were mostly mixed forests, but it was precisely coniferous and deciduous broad-leaved plants that prevailed here, the prosperity of which was absolutely no obstacle to the polar nights.
Neogene
At the initial stage of the Neogene, the climate still remained relatively warm, but a slow trend towards cooling still persisted.
The ice heaps of the northern seas began to melt more and more slowly, until the upper northern shield also began to form.
The climate, due to cooling, began to acquire an increasingly pronounced continental color. It was during this period of the Cenozoic era that the continents became most similar to modern ones. South America merged with North America, and just at that time, climatic zoning acquired similar features to modern ones.
By the end of the Neogene in the Pliocene, the second wave of sharp cooling hit the globe.
Despite the fact that the Neogene was two times shorter than the Paleogene, it was he who was marked by explosive evolution among mammals. It was placental varieties that dominated everywhere.
The main mass of mammals was divided into anchitheria, the ancestors of horse-like and hipparion, also horse-like and three-toed, but gave rise to hyenas, lions and other modern predators.
All kinds of rodents were diverse at that time of the Cenozoic era, the first distinct ostrich-like ones began to appear.
Due to the cooling and the fact that the climate began to acquire an increasingly continental color, areas of ancient steppes, savannahs and light forests expanded, where the ancestors of modern bison, giraffe-like, deer-like, pigs and other mammals grazed in large numbers, which were constantly hunted by the ancient Cenozoic predators.
It was at the end of the Neogene that the first ancestors of humanoid primates began to appear in the forests.
Despite the winters of the polar latitudes, tropical vegetation was still rampant in the equatorial belt of the earth. Broad-leaved woody plants were the most diverse. Consisting of them, as a rule, evergreen forests interspersed and bordered on savannahs and shrubs of other woodlands, subsequently it was they who gave diversity to modern Mediterranean flora, namely olive, plane trees, walnuts, boxwood, southern pine and cedar.
The northern forests were also varied.
There were no evergreens here, but in the majority chestnut, sequoia and other coniferous-broad-leaved and deciduous trees grew and took root. Later, in connection with the second sharp cooling, vast areas of tundra and forest-steppes formed in the north.
The tundras have filled all the zones with the current temperate climate, and the places where until recently tropical forests have grown luxuriantly have turned into deserts and semi-deserts.
Anthropogene (Quaternary period)
In the Anthropogenic period, unexpected warmings alternated with equally sharp cold snaps.
The boundaries of the glacial zone of the Anthropogen sometimes reached 40° northern latitudes.
Cenozoic era (Cenozoic)
Under the northern ice cap were North America, Europe up to the Alps, the Scandinavian Peninsula, the Northern Urals, Eastern Siberia.
Also, in connection with glaciation and the melting of ice caps, there was either a decline or a re-advance of the sea to land. The periods between glaciations were accompanied by marine regression and a mild climate.
At the moment, one of these intervals is taking place, which should be replaced no later than in the next 1000 years by the next stage of icing.
It will last approximately 20 thousand years, until it is again replaced by another period of warming. Here it is worth noting that the alternation of intervals can occur much faster, or it can be completely disturbed due to human intervention in earthly natural processes.
It is likely that the Cenozoic era could be ended by a global ecological catastrophe similar to the one that caused the death of many species in the Permian and Cretaceous periods.
Animals of the Cenozoic era during the Anthropogenic period, together with vegetation, were pushed southward by alternately advancing ice from the north. The main role still belonged to mammals, which showed truly miracles of adaptability. With the onset of cold weather, massive woolly animals appeared, such as mammoths, megaloceros, rhinos, etc.
All kinds of bears, wolves, deer, lynxes also bred strongly. Due to alternating waves of cooling and warming, animals were forced to constantly migrate. A huge number of species died out, and did not have time to adapt to the onset of cooling.
Against the background of these processes of the Cenozoic era, humanoid primates also developed.
They increasingly improved their skills in the possession of all kinds of useful objects and tools. At some point, they began to use these tools for hunting purposes, that is, for the first time, tools of labor acquired the status of weapons.
And since then, a real threat of extermination has hung over various species of animals. And many animals, such as mammoths, giant sloths, North American horses, which were considered by primitive people to be commercial, were completely destroyed.
In the zone of alternating glaciations, the tundra and taiga regions alternated with forest-steppe, and tropical and subtropical forests were strongly pushed to the south, but despite this, most plant species survived and adapted to modern conditions.
The dominant forests between periods of icing were broad-leaved and coniferous.
At the present moment of the Cenozoic era, man reigns everywhere on the planet. He randomly interferes in all sorts of earthly and natural processes. Over the past century, a huge amount of substances have been released into the earth's atmosphere, contributing to the formation of the greenhouse effect and, as a result, faster warming.
It is worth noting that the more rapid melting of ice and the rise in the level of the world ocean contributes to the disruption of the general picture of the climatic development of the earth.
Due to future changes, undercurrents may be disrupted, and, as a result, the general planetary intra-atmospheric heat exchange, which may lead to even more massive icing of the planet following the warming that has begun at the moment.
It is becoming more and more clear that how long the Cenozoic era will be, and how it will eventually end, will now depend not on natural and other natural forces, but on the depth and arrogance of human intervention in global natural processes.
To the table of the Phanerozoic eon
Cenozoic (Cenozoic era) - the latest era in the geological history of the Earth with a length of 65.5 million years, starting with the great extinction of species at the end of the Cretaceous period. The Cenozoic era is still going on.
Cenozoic era
Translated from Greek as "new life" (καινός = new + ζωή = life). The Cenozoic is divided into the Paleogene, Neogene and Quaternary period (anthropogen).
Historically, the Cenozoic was divided into periods - Tertiary (from Paleocene to Pliocene) and Quaternary (Pleistocene and Holocene), although most geologists no longer recognize such a division.
period 3: Paleogene, Neogene and Quaternary
Cenozoic (Cenozoic era) - the latest era in the geological history of the Earth with a length of 65.5 million years, starting with the great extinction of species at the end of the Cretaceous period.
The Cenozoic era is still going on. Translated from Greek as "new life" (καινός = new + ζωή = life). The Cenozoic is divided into the Paleogene, Neogene and Quaternary period (anthropogen). Historically, the Cenozoic was subdivided into periods - TERTIARY (FROM PALEOCENE TO PLIOCEN) and QUARTER (PLEISTOCENE AND HOLOCENE), although most geologists no longer recognize such a division.
http://ru.wikipedia.org/wiki/Cenozoic_era
The Cenozoic era is subdivided into the Paleogene (67 - 25 million years), Neogene (25 - 1 million years).
The Cenozoic era is divided into three periods: Paleogene (lower Tertiary), Neogene (higher Tertiary), Anthropogen (Quaternary)
Cenozoic era The last stage in the development of life on Earth is known as the Cenozoic era. It lasted about 65 million years.
years and is of fundamental importance from our point of view, since it was at this time that primates developed from insectivores, from which man descends. At the beginning of the Cenozoic, the processes of Alpine folding reach their climax; in subsequent epochs, the earth's surface gradually acquires its modern outlines.
Geologists divide the Cenozoic into two periods: Tertiary and Quaternary. Of these, the first is much longer than the second, but the second - the Quaternary - has a number of unique features; this is the time of the ice ages and the final formation of the modern face of the Earth. The development of life in the Cenozoic era reached its peak in the history of the Earth. This is especially true for marine, flying and terrestrial species.
From a geological point of view, it was during this period that our planet acquired its modern appearance. Thus, New Guinea and Australia are now independent, although they were previously annexed to Gondwana.
These two territories have shifted closer to Asia. Antarctica, as it has become in its place, and remains on it to this day. The territories of North and South America were connected, but nevertheless today they are divided into two separate continents.
Paleogene, Neogene and Quaternary
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