The first animals on land were protozoa. Many millions of years ago: the world's first animals. The most ancient bird - protoavis
Humanity owes the emergence of natural diversity on Earth to billions of years of revolution. Modern geologists and paleontologists have discovered turning points in the development of life on our planet.
1. The oldest people - Omo
Humans can now trace their lineage back hundreds of thousands of years. Two skulls, named Omo 1 and Omo 2, which were discovered in Ethiopia in 1967, are 195,000 years old, making them the earliest anatomically modern humans discovered so far. Scientists now think that Homo sapiens began to evolve 200,000 years ago.
However, this is still a matter of controversy, as evidence of cultural development - found musical instruments, needles and jewelry - dates back only 50,000 years. Complex compound tools such as harpoons also appeared around this time. Therefore, no one can answer the simple question: if modern humans appeared 200,000 years ago, then why did it take them as much as 150,000 years to develop anything resembling a culture.
2. The most ancient bird - protoavis
Today, everyone knows that birds evolved from dinosaurs, and also that many dinosaurs were actually covered in feathers. As a result, the question "which bird is the most ancient" should essentially be reformulated into "at what point can dinosaurs be considered birds."
For a long time, paleontologists considered the Archeopteryx to be the most ancient birds, but today an even more ancient candidate for the title of the first bird has appeared. Protoavis lived about 220 million years ago, 80 million years earlier than any of its competitors. The fossil was found in Texas by paleontologist Sankar Chatterjee, who claims that Protoavis is actually closer to modern birds than Archeopteryx.
3. The first types of creatures that began to walk on earth - Tiktaalik and pneumodesmus
Tiktaalik, a duck-billed creature that lived in the Devonian period, was a cross between a fish, a frog and an alligator. It is believed that it first got out of the water on land 375 million years ago. Discovered in Canada in 2004, this species is considered an important transitional link between aquatic vertebrates and the first land animals. Tiktaalik can also boast of ribs that are able to support its body out of water, a light, mobile neck and eyes on the top of its head, like a crocodile. The centipede pneumodesmus lived about 428 million years ago. The 1 centimeter-sized creature was actually the first creature to live permanently on earth and breathe air.
4. The oldest reptile - Gilon
Reptiles were the first vertebrates that could live on earth. The lizard-like creature, the Gilon, which is only 20 centimeters long, is believed by scientists to be the oldest reptile. Hylonomas, which appear to have been insectivorous, arose about 310 million years ago. The surviving fossil of this creature was discovered in 1860 inside a tree trunk in Nova Scotia.
5. The oldest creature that can fly - rhinognath
Flying as a primary means of locomotion requires a complex body structure (low body weight but strong skeleton) as well as powerful wing muscles. The first creature that was able to fly is actually the oldest known insect. Rhyniognatha hirsti is a tiny insect that lived about 400 million years ago. The first evidence of the existence of this insect was discovered in 1928 in the Devonian rocks.
6. The first flowering plant - potomacapnos and amborella
People tend to associate plants with flowers, but flowers are actually relatively recent. Before flowers appeared, plants reproduced with spores for hundreds of millions of years. In fact, scientists don't even know why flowers came into being, as they are very delicate and whimsical, and also require a huge amount of energy, which theoretically could be put to a much more rational use.
These incomprehensible circumstances led Darwin to describe the growth of flowers as a "terrible secret." The oldest known fossil flowering plants date back to the Cretaceous, between 115 and 125 million years ago. Some of the oldest flowers are potomacapnos, which surprisingly resembles a modern poppy, as well as amborella, which was found on the island of New Caledonia. Everything points to the fact that flowers did not develop slowly, but suddenly arose in fact in their modern form.
7. The most ancient mammal - Hadrocodium
The oldest known mammal resembled a small mouse or a modern shrew. The length of the hadrocodium, the remains of which were found in China in 2001, was about 3.5 centimeters, and the animal weighed only 2 grams. Most likely, he led a lifestyle similar to the modern shrew, since his teeth were special fangs for grinding insects. The Hadrocodium lived about 195 million years ago, long before some of the most famous dinosaurs, including Stegosaurus, Diplodocus, and Tyrannosaurus Rex.
8. The first tree is vattieza
Trees have played (and still play) a crucial role in shaping the Earth's atmosphere. Without them, carbon dioxide would not turn into oxygen, and the planet would soon become lifeless. The first forests dramatically changed the Earth's ecosystem. Thus, the appearance of trees can be considered one of the most important evolutionary breakthroughs in history.
Currently, the oldest known tree is a 397-million-year-old species that has been named vattieza. The leaves of this fern-like plant resembled a palm, and the tree itself reached a height of 10 meters. Wattiesa arose 140 million years before the dinosaurs. The plant reproduced by spores similar to modern ferns and mushrooms.
9. The oldest dinosaur - nyasasaurus
Dinosaurs began to reign on Earth after the Permian mass extinction, which occurred about 250 million years ago and destroyed about 90 percent of all species on the planet, including 95 percent of marine life, and most of the planet's trees. After that, dinosaurs appeared in the Triassic.
The oldest dinosaur known to date is Nyasasaurus, whose bones were discovered in Tanzania in 1930. Until now, scientists have no idea whether he was a predator or herbivore, and he also walked on two legs or four. The height of the nyasasaurus was only 1 meter, and the weight was 18-60 kg.
10 Oldest Life Form
What is the oldest form of life known to science? This is a rather difficult question, since often the fossils are so ancient that their age is difficult to accurately determine. For example, rocks discovered near the Pilbara region in Australia contained microbes nearly 3.5 billion years old. However, some scientists believe that such Precambrian organ-walled microfossils are actually a strange form of minerals that arose under special hydrothermal conditions. In other words, they are not alive.
To live on land, animals need lungs that allow them to extract oxygen from the air. Without lungs, aquatic animals would suffocate and die as soon as they surfaced. But the moment came when many living beings learned to breathe atmospheric air.
Amphibians
The first animals that inhabited the land protruding from the water were amphibians. They never ventured far from the water, because they laid their eggs in the water to breed. The frogs that live in ponds do the same now.
These were:
- Dolohosoma
- Urocordilus
At the time when the first animals came out of the water, the fish also changed a lot. Most of them have already become similar to modern fish.
Insects
The noise of wings has already begun to be heard in the ancient forests. These were some creatures, descendants of water scorpion shrimp and other species, which had wings and began to fly. This is how insects were born. There were no birds yet. The most ancient insects were dragonflies. Some of them had a wingspan of up to half a meter.
How were the first amphibians born?
It is possible that some fish acquired the ability to breathe on land for a short time when their water body dried up. They crawled on the ground in search of water, so as not to die. Some of them gradually learned to live on earth.
Instruction
According to abiogenic hypotheses about the origin of life on Earth, the first step towards the origin of living things was the synthesis of organic biopolymers. Through chemical evolution, biopolymers passed to the first living organisms, which further developed according to the principles of biological evolution. In the course of this historical development and complication, many forms of life have appeared.
The history of the Earth is divided into long time intervals - eras: Katarchean, Archean, Proterozoic, Paleozoic, Mesozoic and Cenozoic. Paleontology, the science of ancient organisms of past geological eras, helps scientists to obtain data on the development of life on Earth. Fossil remains - mollusk shells, fish teeth and scales, egg shells, skeletons and other hard parts - are used to study organisms that lived tens, hundreds of millions of years ago.
It is believed that in the Archean (“earliest”) era, bacteria dominated the planet, the result of their vital activity was marble, graphite, limestone, etc. Remains of cyanobacteria capable of oxygen-free photosynthesis were also found in Archean deposits. At the end of the most ancient era, living organisms, according to assumptions, were divided into prokaryotes and eukaryotes.
In the Proterozoic - the era of early life - living organisms continued to become more complex, and their methods of nutrition and reproduction improved. All life was concentrated in the aquatic environment and along the banks of water bodies. Among animals, a wide variety of coelenterates and sponges appeared. Toward the end of the Proterozoic era, all types of invertebrates and the first chordates arose. Remains of worms, mollusks and arthropods are also found in the sediments. The only descendant of the early life era that has survived to this day is considered the lancelet.
The Paleozoic is the era of "ancient life". It distinguishes the Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian periods. At the beginning of the Paleozoic, Cambrian, invertebrates appeared, covered with a solid skeleton built from chitin, calcium carbonate and phosphate, silica. The fauna was mainly represented by benthic organisms - coral polyps, sponges, worms, archeciata, echinoderms and arthropods. Trilobites - the oldest arthropods - have reached their greatest prosperity.
The Ordovician is characterized by the strongest flooding of the Earth and the appearance of a multitude. Arthropods and mollusks were especially widespread during this period, but the first jawless vertebrates also appeared.
In the Silurian, animals and plants came to land. The first were arachnids and centipedes, apparently descended from trilobites. In the Devonian period, primitive jawed fish arose, having a cartilaginous skeleton and covered with a shell. Sharks and lobe-finned fish originated from them, and the first amphibians (ichthyostegi, stegocephals) originated from lobe-finned fish, which are already able to breathe atmospheric air.
In the Carboniferous period, the period of swamps and vast swamp forests, amphibians flourished and the first insects appeared - cockroaches, dragonflies, beetles. Primitive reptiles also appeared, inhabiting drier places. In Perm, the climate became drier and cooler, which led to the extinction of trilobites, large mollusks, large fish, large insects and arachnids. Reptiles were the most numerous at this time. The ancestors of mammals appeared - therapsids.
In the Mesozoic, the Triassic, Jurassic and Cretaceous periods are distinguished. In the Triassic, many reptiles (turtles, ichthyosaurs, crocodiles, dinosaurs, plesiosaurs) and insects arose. At the end of the period, the first representatives of warm-blooded animals appeared. In the Jurassic period, dinosaurs reached their peak of development, the first birds similar to reptiles appeared.
In the Cretaceous, marsupials and placental mammals arose. At the end of the Cretaceous there was a mass extinction of many animal species - dinosaurs, large reptiles, etc. Scientists attribute this to climate change and general cooling. Advantages in the struggle for survival were received by warm-blooded animals - birds and mammals, which flourished in the Cenozoic - the era of new life, consisting of periods of the Paleogene, Neogene and Anthropogen.
This strange multi-legged creature was one of the first animals to walk on land.
Pioneers of life on land
The oldest known terrestrial invertebrate fossils are 400 million years old. They look like scorpions and belong to a group of arthropods that have an articulated body covered with a shell, which is well preserved in the fossil state. It can be assumed that in that era worms and some mollusks lived on land, but their soft body is poorly preserved, so they did not leave any traces. Paleontologists believe that the true pioneers of land conquest appeared several million years earlier and that they are probably very close to modern tardigrades. These tiny animals, not exceeding 1 mm in length, teem with thin films of water that cover mosses and lichens. They are able to survive even if their habitat dries up: their body is almost completely dehydrated and remains viable for many years. Such an ability could allow these animals, regularly deprived of water, to be the first to gradually conquer the land.
First insects
During the Devonian period (400-360 million years ago) and the following Carboniferous period, arthropods spread rapidly on land. Different groups of animals appeared: millipedes, soft-footed animals (animals similar to slugs, but with primitive legs), arachnids (resembling modern ticks). Some species reached considerable sizes, such as, for example, the giant centipede Arthropleura (1.8 m), the largest arthropod that has ever existed on land. Despite its impressive appearance, this harmless animal ate only plants.
Before him, the first microscopic insects, springtails, were a few tenths of a millimeter in size. These primitive wingless animals exist everywhere: they live under the bark of trees, under stones, in moss. Since the Carboniferous period, cockroaches and mayflies have been no different from their modern descendants. Although scorpions were among the first animals to conquer land, for a long time (up to the Carboniferous period) they remained amphibians and lived without moving away from the water.
Wings to fly
All these terrestrial arthropods were vegetarians and were devoid of wings until predators appeared, mainly spiders and scorpions, fully adapted to life on land. It was with the advent of these predators that insects acquired an excellent means of escaping from them - flight. For 50 million years, insects were the only animals able to fly. Meganeura, a huge dragonfly with a wingspan of more than 70 cm, flew in the forests of the Carboniferous period.
Carapace and limbs
Arthropleura is a giant centipede (1.8 m long). Despite its intimidating appearance, it ate plants.
It is difficult to explain what caused the first invertebrates to leave the water. Perhaps pursued by marine predators, they had no choice if they wanted to survive. However, life on land is hostile and difficult: the lack of water threatens animals with dehydration, gravity presses them to the ground, and one must be able to breathe oxygen from the air, not from water. But, according to scientists, the first terrestrial invertebrates had a double advantage: a shell that protected them from the effects of gravity, and limbs for movement. Muscles that control the limbs are attached to the shell. This shell (called the cuticle in insects) is waterproof and therefore prevents the animal from dehydration. Thus, the shell allows animals to survive in arid places. Worms that do not have a shell are forced to burrow into the damp earth.
Insects, masters of the earth
It is believed that the Earth is most densely populated by mammals, to which man also belongs. But the development of insect diversity has been even more successful. In the Mesozoic era (245-65 million years ago), insects were already very numerous, and in the Cenozoic era, the number of insect species especially increased. Today, while mammals represent 3,600 species, the insect class numbers about 800,000, and it is estimated that 5 times as many more are yet to be discovered. The bronze beetle (see photo) belongs to the group of beetles, which includes 280,000 species (scarabs, ladybugs, etc.).
How do insects breathe?
On the abdomen of this locust, a series of small holes can be distinguished: these are breathing holes called spiracles. Air enters through them and is sent to the cells of the body through the smallest, very thin tubes - the trachea. This system is effective only for small animals. She allowed insects to master the land, but she also limited their growth. Spiders, scorpions, snails do not have tracheae, they breathe with very simple lungs. Insect blood serves only to carry nutrients and waste. Their blood is transparent because it does not contain the red pigment hemoglobin, which carries oxygen in the blood of vertebrates.
Some time after the plants, the first animals left the water to settle on land. These were invertebrate animals belonging to arthropods. Their body was covered with a shell, they moved underwater thanks to their jointed limbs. Gradually, these animals emerged from the water and learned to move on land. At first they lived in damp places, near ponds and rivers. Then they improved and began to dare to go farther and farther from the water. Finally, they grew, reaching impressive sizes.
Pterosaurs
History of animal evolution
Ichthyostega's skull was similar to that of a lobe-finned fish Eusthenopteron, but a pronounced neck separated the body from the head. While the Ichthyostega had four strong limbs, the shape of its hind legs suggests that this animal did not spend all of its time on land.
The first reptiles and the amniotic egg
Hatching a turtle from an egg
One of the greatest evolutionary innovations of the Carboniferous (360 - 268 million years ago) was the amniotic egg, which allowed early reptiles to move away from coastal habitats and colonize dry areas. The amniotic egg allowed the ancestors of birds, mammals and reptiles to breed on land, and prevent the embryo inside from drying out, so you could do without water. It also meant that, unlike amphibians, reptiles were able to produce fewer eggs at any given time, as the risks of hatchlings were reduced.
The earliest date for the development of an amniotic egg is about 320 million years ago. However, reptiles were not exposed to any significant adaptive radiation for about 20 million years. The current thinking is that these early amniotes still spent time in the water and came ashore mainly to lay their eggs rather than feed. Only after the evolution of herbivores did new groups of reptiles emerge that could exploit the abundant floristic diversity of the Carboniferous.
Hylonomus
The early reptiles belonged to an order called the captorhinids. Gilonomus were representatives of this detachment. They were small, lizard-sized animals with amphibian skulls, shoulders, pelvis, and limbs, as well as intermediate teeth and vertebrae. The rest of the skeleton was reptilian. Many of these new "reptilian" features are also seen in small, modern amphibians.
First mammals
Dimetrodon
A major transition in the evolution of life occurred when mammals evolved from a single lineage of reptiles. This transition began during the Permian period (286 - 248 million years ago), when a group of reptiles that included the Dimetrodons gave birth to the "terrible" therapsids. (Other large branches, sauropsids, gave rise to birds and modern reptiles.) These reptilian mammals in turn gave birth to cynodonts such as Thrinaxodon ( Thrinaxodon) during the Triassic period.
Trinaxodon
This evolutionary line provides an excellent series of transitional fossils. The development of a key mammalian feature, the presence of a single bone in the lower jaw (compared to several in reptiles), can be traced in the fossil history of this group. It includes excellent transitional fossils, Diarthrognathus and Morganucodon, whose lower jaws have both reptilian and mammalian articulations with the upper ones. Other new features found in this lineage include the development of different types of teeth (a feature known as heterodontia), the formation of a secondary palate, and an increase in dentary bone in the lower jaw. The legs are located directly below the body, an evolutionary advance that occurred in the ancestors of the dinosaurs.
The end of the Permian period was marked by perhaps the greatest. According to some estimates, up to 90% of the species became extinct. (Recent studies have suggested that this event was caused by an asteroid impact that triggered climate change.) During the subsequent Triassic period (248 to 213 million years ago), the survivors of the mass extinction began to occupy vacant ecological niches.
However, at the end of the Permian, it was dinosaurs, not reptile mammals, that took advantage of the new available ecological niches to diversify into dominant land vertebrates. In the sea, ray-finned fish began a process of adaptive radiation that made their class the most species-rich of all classes of vertebrates.
Dinosaur classification
One of the major changes in the group of reptiles that gave birth to the dinosaurs was in the posture of the animals. The arrangement of the limbs has changed: previously they protruded on the sides, and then began to grow directly under the body. This had major implications for locomotion, as it allowed for more energy-efficient movements.
Triceratops
Dinosaurs, or "terrible lizards", are divided into two groups based on the structure of the hip joint: lizards and ornithischians. Ornithischians include Triceratops, Iguanodon, Hadrosaurus, and Stegosaurus). The lizards are further subdivided into theropods (eg Coelophysis and Tyrannosaurus Rex) and sauropods (eg Apatosaurus). Most scientists agree that from theropod dinosaurs.
Although dinosaurs and their immediate ancestors dominated the terrestrial world during the Triassic, mammals continued to evolve during this time.
Further development of early mammals
Mammals are highly developed synapsids. Synapsids are one of the two great branches of the amniote family tree. Amniotes are a group of animals that are characterized by having embryonic membranes, including reptiles, birds, and mammals. Another large amniotic group, the Diapsid, includes birds and all living and extinct reptiles except turtles. Turtles belong to the third group of amniotes - Anapsids. Members of these groups are classified according to the number of openings in the temporal region of the skull.
Dimetrodon
Synapsids are characterized by the presence of a pair of accessory openings in the skull behind the eyes. This discovery gave synapsids (and similarly diapsids, which have two pairs of holes) stronger jaw muscles and better biting abilities than early animals. Pelycosaurs (such as Dimetrodon and Edaphosaurus) were early synapsids; they were reptilian mammals. Later synapsids included therapsids and cynodonts, which lived during the Triassic period.
cynodont
Cynodonts shared many characteristic mammalian features, including a reduced number or complete absence of lumbar ribs, suggesting a diaphragm; well developed fangs and secondary palate; increased size of the dentition; holes for nerves and blood vessels in the lower jaw, indicating the presence of whiskers.
About 125 million years ago, mammals had already become a diverse group of organisms. Some of these would have been similar to today's monotremes (such as the platypus and echidna), but early marsupials (a group that includes modern kangaroos and opossums) were also present. Until recently, placental mammals (the group to which most living mammals belong) were thought to be of a later evolutionary origin. However, recent discovered fossils and DNA evidence suggest that placental mammals are much older, and may have evolved over 105 million years ago.
Note that marsupials and placental mammals provide excellent examples of convergent evolution, where organisms that are not particularly closely related developed similar body shapes in response to similar environmental exposures.
Plesiosaurs
However, despite the fact that mammals had what many consider "advanced", they were still minor players on the world stage. When the world entered the Jurassic period (213 - 145 million years ago), the dominant animals on land, in the sea and in the air were reptiles. Dinosaurs, more numerous and unusual than during the Triassic, were the main land animals; crocodiles, ichthyosaurs, and plesiosaurs ruled the sea, and pterosaurs populated the air.
Archeopteryx and the evolution of birds
Archeopteryx
In 1861, an intriguing fossil was discovered in the Solnhofen Jurassic limestone in southern Germany, a source of rare but exceptionally well-preserved fossils. The fossil seemed to combine features of both birds and reptiles: a reptilian skeleton accompanied by a clear imprint of feathers.
While Archeopteryx was originally described as a feathered reptile, it has long been considered a transitional form between birds and reptiles, making it one of the most important fossils ever discovered. Until recently, it was the earliest known bird. Recently, scientists have realized that Archeopteryx bears more resemblance to the maniraptors, a group of dinosaurs that includes the infamous Jurassic Park velociraptors, than to modern birds. Thus, Archeopteryx provides a strong phylogenetic relationship between the two groups. Fossil birds have been found in China that are even older than Archeopteryx, and other feathered dinosaur discoveries support the theory that theropods evolved feathers for insulation and thermoregulation before birds used them for flight.
Looking closer at the early history of birds is a good example of the concept that evolution is neither linear nor progressive. The bird lineage is erratic and many "experimental" forms appear. Not everyone achieved the ability to fly, and some looked nothing like modern birds. For example, Microraptor gui, which appears to have been a flying animal with asymmetrical flight feathers on all four limbs, was a dromaeosaurid. Archeopteryx itself did not belong to the lineage from which true birds evolved ( Neornithes), but was a member of the now-extinct enanciornis birds ( Enantiornithes).
End of the Dinosaur Age
Dinosaurs spread throughout the world during the Jurassic, but during the subsequent Cretaceous (145 - 65 million years ago) their species diversity declined. In fact, many of the typically Mesozoic organisms such as ammonites, belemnites, ichthyosaurs, plesiosaurs, and pterosaurs were in decline during this time, despite still giving rise to new species.
The emergence of flowering plants during the Early Cretaceous caused a major adaptive radiation among insects: new groups such as butterflies, moths, ants and bees emerged. These insects drank the nectar from the flowers and acted as pollinators.
The mass extinction at the end of the Cretaceous, 65 million years ago, wiped out the dinosaurs, along with any other land animal weighing more than 25 kg. This paved the way for the expansion of mammals on land. In the sea at this time, fish again became the dominant vertebrate taxon.
modern mammals
At the beginning of the Paleocene (65 - 55.5 million years ago), the world was left without large land animals. This unique situation was the starting point for a great evolutionary diversification of mammals, which were previously nocturnal animals the size of small rodents. By the end of the era, these representatives of the fauna occupied many of the free ecological niches.
The oldest confirmed primate fossils are about 60 million years old. Early primates evolved from ancient nocturnal insectivores, something like shrews, and resembled lemurs or tarsiers. They were probably arboreal animals and lived in or subtropical forests. Many of their characteristic features were well suited to this habitat: gripping hands, rotating shoulder joints, and stereoscopic vision. They also had a relatively large brain size and claws on their fingers.
The earliest known fossils of most modern orders of mammals appear in a short period during the early Eocene (55.5-37.7 million years ago). Both groups of modern ungulates - artiodactyls (a detachment to which cows and pigs belong) and equids (including horses, rhinos and tapirs) became widespread throughout North America and Europe.
Ambulocetus
At the same time that mammals were diversifying on land, they were also returning to the sea. The evolutionary transitions that led to whales have been extensively studied in recent years with extensive fossil finds from India, Pakistan and the Middle East. These fossils point to a change from terrestrial Mesonychia, which are the likely ancestors of whales, to animals such as Ambulocetus and primitive whales called Archaeocetes.
The trend towards a cooler global climate that occurred during the Oligocene epoch (33.7-22.8 million years ago) contributed to the emergence of grasses, which were to spread to vast grasslands during the subsequent Miocene (23.8-5.3 million years ago). ). This change in vegetation led to the evolution of animals, such as more modern horses, with teeth that could handle the high silica content of grasses. The cooling trend has also affected the oceans, reducing the abundance of marine plankton and invertebrates.
Although DNA evidence suggests that hominids evolved during the Oligocene, abundant fossils did not appear until the Miocene. Hominids, on the evolutionary line leading to humans, first appear in the fossil record during the Pliocene (5.3 - 2.6 million years ago).
During the entire Pleistocene (2.6 million - 11.7 thousand years ago) there were about twenty cycles of cold ice age and warm interglacial periods at intervals of about 100,000 years. During the Ice Age, glaciers dominated the landscape, snow and ice spread into the lowlands, and transported vast amounts of rock. Because a lot of water was locked up on the ice, the sea level dropped to 135 m than it is now. Wide land bridges allowed plants and animals to move. During warm periods, large areas were again submerged under water. These repeated episodes of environmental fragmentation resulted in rapid adaptive radiation in many species.
The Holocene is the current epoch of geological time. Another term that is sometimes used is the Anthropocene because its main characteristic is the global changes caused by human activities. However, this term can be misleading; modern humans were already created long before the beginning of the era. The Holocene epoch began 11.7 thousand years ago and continues to the present day.
Mammoths
When warming came on Earth, she gave way. As the climate changed, very large mammals that adapted to extreme cold, such as the woolly rhinoceros, became extinct. Humans, once dependent on these "mega-mammals" as their main source of food, have switched to smaller animals and started harvesting plants to supplement their diet.
Evidence shows that around 10,800 years ago, the climate underwent a sharp cold turn that lasted several years. The glaciers did not return, but there were few animals and plants. As temperatures began to recover, animal populations grew and new species emerged that still exist today.
Currently, the evolution of animals continues, as new factors arise that force representatives of the animal world to adapt to changes in their environment.