What Was the Earth Like after Dinosaurs?

roughly 66 million years ago our planet went through one of the most large-scale extinction events in the history of multicellular life-forms entire classes of species were wiped off the face of the earth others changed beyond all recognition in order to adapt to the new conditions and survive the reasons for this dramatic event are still not known for certain still, there is no doubt that the cretaceous Paleogene extinction made great changes to what our planet looked like the majestic and horrifying dinosaurs were superseded by creatures not less impressive mammals three-fourths of all living organisms on earth died out in the cretaceous Paleogene extinction almost all creatures heavier than 25 kilos ceased to be including practically all non-avian dinosaurs this tragic event heralded the end of the Mesozoic and the beginning of the Cenozoic the geologic era that is still not over it is divided into three periods of various duration which are different both in terms of climate and diversity of the biosphere the first and longest is known as the Paleogene it began around 66 million years ago and continued for 43 million years in the first 10 million years of the Paleogene the earth's biosphere was recovering from the hard blow dealt by the mass extinction this geological epoch is referred to as the Paleocene since great numbers of dinosaurs and other species of the cretaceous had perished there were lots ofvacant ecological niches for the taking these were promptly filled by the new masters of our planet mammals the geography of the earth of that period was drastically different from what we're used to seeing today looking at a map of that prehistoric earth we would already be able to make out the familiar continents but they were positioned slightly differently thus, north and south Americas were separated by tropical seas while the Indian subcontinent was just starting to make for the Asian shores the prehistoric ocean known as the tethers still lay between Africa and Eurasia but was already largely giving way due to the movements of tectonic plates the climate of the epoch was warmer and more stable than today's most of the planet was covered with dense and lush tropical forests the overwhelming majority of the living creatures of the day were quite small thanks to the abundance of vegetable food they quickly propagated and spread across more and more new areas this is when the prehistoric ancestors of most of today's mammals thrived for example, the warm forests of the Paleogene were inhabited by my acids small and deft predators that looked like martins it is believed that they were the progenitors of all today's rich diversity of mammal predators at around the same time their lived archaeo seats the prehistoric ancestors of today's whales at the time however they looked more like hippos they hadn't gone to live in the sea yet but had made their first steps in that direction their limbs respiratory organs in the inner rear had already started to adapt to prolonged stays underwater the next step our planet went through was the ear scene it began approximately 56 million years ago and continued for slightly over 22 million years the contours of the continents had already grown to be quite recognizable India had finally made it to the southern shores of Asia and as a result of the collision of tectonic plates giant rock folds formed that is how the Himalayas rose the largest mountain range on our planet today even though some species of that time already looked like some we might come across today others were completely different an example of one of these is Andrew Sarkis one of the largest mammal predators that has ever lived on the earth its skull measured up to 84 centimeters which is roughly one and a half times more than that of the brown bear and its bite is estimated to have been harder than that of any of today's land predators it has been inferred from the deep tooth sockets in Andrew Sarkis's skull where mandible muscles were attached to which leaves no doubts as to the bite's crushing force reconstruction of its skeleton shows that the animal could measure over 4 meters in length and weigh as much as a ton still interestingly it looks like this giant carnivore fell into the class of primitive angulates research showed that Andrew Sarkis's closest relatives were the prehistoric sewer forms hippopotamus and cetaceans studies of a few unearthed fossils with skull and teeth show that the animal must have been omnivorous and even didn't mind eating carrion unfortunately, not many bones and fossils of this fascinating creature have been found and scientists are still at odds as to the structure of its organism habits and relation to other mammal families the Oligocene was the last Debuck of the Paleogene it is posited that it began around 33.9 million years ago and was over about 23 million years ago which makes it roughly 11 million years long this was a time of global cooling warm tropical forests were gradually superseded by endless prairies covered with grasslands this is when the Antarctic glaciation began and an icy shield transformed the green continent of the pearl into a lifeless cold desert Australia continued to drift away from the other continents while Africa on the contrary was making for the north to meet Europe after a collision of tectonic plates mountain ranges formed and that is how the alps made their appearance on the map of the world around 26 28 million years ago the super volcano lagarita furiously erupted on the territory of today's Colorado in fact, it was one of the major volcanic emissions of the entire phanerozoic eon an area of over 30 000 square meters was buried under a layer of hot ash as much as a hundred meters thick all life within a huge radius around the volcano was destroyed completely amazingly life is able to come to terms with any disasters the earth of the time was inhabited by fascinating creatures some of which were not smaller than dinosaurs in size for example intricate theorem a prehistoric herbivore related to rhinos par Aceratherium the largest of these reached 4.8 meters in shoulder length which is higher than a large African elephant thanks to their remarkably long neck these giants were able to raise their head up to seven meters above the ground today's rhino would be able to pass under its enormous progenitor's belly while a human would hardly reach up to touch its knee with our mass reaching 20 tons these giants were the largest land mammals of all times even brontosaurus the most massive of land dinosaurs weighed just around 15 tons it still hasn't been established for certain what Endrick Ethereum looked like unfortunately not one entire skeleton of these amazing animals has been excavated so far only separate fragments from different animals of the species most scientists agree that in spite of their relation to rhinos end uric Ethereum didn't have a massive horn although it may well have had a small nose trunk like today's tapias the trunk would have allowed it to pick juicy leaves off treetops this giant herbivores must have lived in small herds and were constantly on the move around vast stretches of land roaming across their dominions in search of food unfortunately, by the end of the Oligocene indrick Ethereum had died out completely at around the same time the areas they used to inhabit were explored by prehistoric elephants alongside large predator's hyena dawns and damphi cyanides the latter's are also known as bear dogs it is thought that the emergence of new large herbivores would have greatly upset nature's balance and intricate theorem would have been forced to fiercely compete for its food famine and the threat from the new dwellers of the Asian prairie gradually led to the herbivores giant's total extinction apart from those mentioned there were some other large predators who were quite common on the earth in the period from 37.2 to 28.4 million years ago and tele dance fossilized remains of these creatures have been found all over Eurasia being even-toed ungulates and telodons resembled wild boars although in terms of evolution these creatures are closer to hippos or even cetaceans measuring up to two meters in length, they weighed over a ton a meter long head had huge jaws complete with all sorts of teeth sharp in sizes long fangs and wide flat moles it is likely that intelligence were omnivores with a preference for predation not hampered by their impressive size and bulk they were able to develop remarkably high speeds so chances of outrunning such a monster were quite thin a wild boar the size of a large bull that prefers meat posed a serious threat to any inhabitant of the earth of that time that is why it is hardly surprising that intellidons successfully struggled for their survival for such a considerable time the period in the history of our earth that came next was the near gene it began approximately 23 million years ago and ended just two million five hundred and eighty thousand years ago this is when our planet started to look almost but not quite what it looks like today the continents shifted to their today's positions on the planet's surface and the looks of the most of the plants and animals of the day grew to be familiar to our eye with the earth's climate gradually becoming colder and with droughts occurring more often polar caps were gradually growing which culminated in a global glaciation at the end of the Neogene the planet meanwhile was crawling with all sorts of fascinating creatures the deep-sea dwellers were terrorized by megalodon a giant shark measuring 15 meters in length and weighing up to 35 tons on land various gomphotheriids could be seen creatures related to today's elephants many of them were the proud owners of four solid tusks as for the animal's size some were larger than today's African elephant whereas others were quite modest in comparison around 2.5 million years ago there started the quaternary which is currently the last geologic period in the history of the earth it is remarkable for the emergence and evolution of homo sapiens as well as its prehistoric ancestors for example, in the period from one million years ago, to a hundred thousand years ago, there lived Gigantopithecus one of the species of great human-like apes known to science they measured three to four meters in height and weighed over 500 kilograms these creatures lived on the territory of Asia and were related to today's orangutans it appears that Gigantopithecus would not be able to climb trees like other human-like apes on account of its mass however, some of them are known to have dwelt in mountainous areas and made homes and natural grottos caves and ravines even though their diet is believed to have consisted of mainly bamboo bones of herbivorous animals with tooth marks were unearthed in their shelters judging by these finds it is safe to assume that these creatures didn't mind meat and were omnivorous at the very least the Gigantopithecus skeleton is similar to that of a gorilla so they were likely to use all four limbs to move around besides these human-like apes had a comparatively large brain which means that they could be relatively intelligent and were probably able to even make primitive working tools unfortunately, the population of these amazing giants sharply dropped when the prehistoric ancestors of today's human emerged and spread across the planet by around one to three hundred thousand years ago, they had died out completely sadly, not many remains of Gigantopithecus have been found which greatly impedes studying them as they were spreading across the earth primitive human tribes eliminated many other creatures one of their victims was megatherium a giant grounds human tribes came to south America the powerful but sluggish giant was helpless under a barrage of sharp spears and arrows and very soon its population dropped to zero other giants who supposedly became extinct because of humans were diprotodons which inhabited Australia in the period from 1.6 million years ago to around 40 000 years ago these creatures were the largest known marsupials and they were related to wombats and koalas some of these amazing animals reached as much as three meters in length and two meters in shoulder height as for their mass they weighed approximately three tons this makes diprotodons quite as big as some hippos massive and herbivorous they dwelt on massive woodland and coastal grass-covered plains that abounded in Australia before humans had made their appearance there chronologically the extinction of the marsupial giants coincides with first human tribes arriving to this continent still some scientists maintained that the extinction was caused not by hunting but an anomaly of the earth's magnetic field together with a local temperature decrease the height and radiation background coupled with cooling slowed down plant growth which led to famine among the herbivores thus, it appears that by and large the tragedy was inevitable and the humans simply brought it to a close faster the last debacle of the quaternary the Holocene heralded a robust development of the human civilization when homo sapiens spread across the entire planet and dominated all the otherinhabitants of our earth the downside of this evolution is manifested in a number of industrial disasters and irreversible changes in nature's balance for example, it is due to human activity that the greenhouse gases concentration in the earth's atmosphere is getting worse every year this may globally negatively affect all living things on our earth from simplest bacteria to elaborate multicellular organisms unfortunately, the number of fascinating creatures living on our earth is going down every year it is particularly poignant to realize that they perish because of human stupidity or roveries on controlled hunting irresponsible land development and indifference to the environment have already made scientists speak of a new sixth-grade extinction event whose consequences are potentially just as grave as those of the previous five will mankind stop before it eliminates itself how long should it take our planet to recover from the consequences of the technological progress and will nature produce radically new life forms that would weather this crisis just like it happened before.