Scientists estimate that vertebrates inhabit our planet for about 500 million years, 200 million of which are dominated by ancient dinosaurs called dinosaurs. At one time, ancient reptiles were the crown of the creation of mother nature, and their branch - dinosaurs - generally represented the peak of development of all reptiles that ever inhabited our planet. All kinds of dinosaurs, like their way of life, were replaced in different eras, and nature introduced new corrections to their life.
Who are paleontologists?
Before you and I know what kind of dinosaurs there have been on our planet in different eras, it is necessary to understand how it all began. The study of life, which originated in distant eras, is the science of paleontology. Its name comes from three Greek words: "paleos" - ancient, "ontos" - creature, "logos" - word. People involved in this science are called paleontologists. Their work is somewhat reminiscent of the work of detectives: paleontologists need to restore an integral picture of bygone ages from the fragmented fragments and remains. A huge role in this is played by their intuition, combined with logic and imagination.
Even the most insignificant facts need careful investigation. Paleontologists collect them bit by bit. This is quite painstaking and exhausting work, because many events of the past irrevocably went into oblivion, without even leaving a single trace in the rocks. It is thanks to the labors of these people that we can learn about exactly which animals once inhabited the planet Earth, what types of dinosaurs existed, how they looked, how they lived, who they hunted, how they were saved from certain dangers. Paleontologists were able to recreate bit by bit the picture of the world around the great era of dinosaurs.
How was the era of dinosaurs formed?
Of course, all types of dinosaurs and species branching from them during the great era of reptiles could not have become so numerous and widespread if our planet had not developed and formed accordingly. The era of dinosaurs is usually divided into several periods. We will briefly consider each of them.
- Archean. This is the very first, earliest period. This is the starting point, from where the era of reptiles originates. At this time, life was just beginning to emerge on Earth, the evolution of unicellular organisms was taking place.
- Proterozoic. During this period, multicellular animals and plants began to appear on the planet.
- Cambrian In the Cambrian period, life on Earth began to actively develop, algae and aquatic invertebrate animals appeared.
- Ordovician. This time is marked by the appearance of the first vertebrate creatures on the planet.
- Silur. In the Silurian period, invertebrates and some species of plants move from water to land.
- Devonian. This time is characterized by the appearance of gymnosperms, as well as animals such as amphibians, arachnids (spiders, ticks), insects.
- Carbon It is from here that the era of ancient reptiles originates. Reptiles that appeared during this period were divided into three branches: anapsid, synapsid, diapsid. At the same time, the first conifers and flying insects began to appear on the planet.
- Permian. The Permian period was marked by the appearance of the first bugs, bugs, hymenoptera, the first small lizards and the first archosaurs.
- Triassic. Paleontologists found that it was at this time that the first flies began to inhabit our planet, while the last ancient amphibians - stegocephals - began to die out. Representatives of the Anapsid class also died out. In the Triassic period, the first crocodiles, turtles, flying lizards, mammals and, of course, dinosaurs appeared.
- Yura. The Jurassic period is a kind of culmination of the dinosaur era. It was at this time that angiosperms appeared on Earth, butterflies began to fly, some modern amphibians (the same green frogs) were born, ancient birds (archeopteryx) and, of course, new species of dinosaurs appeared. In the Jurassic period, the last representatives of the synapsid class began to die out.
- A piece of chalk. Angiosperms finally conquered the land. Modern species of ants and blood-sucking insects have appeared. In addition, the Cretaceous period is the end of the great era of reptiles: it was at this time that the complete extinction of dinosaurs, marine reptiles, pterosaurs took place. The Cretaceous period was marked by the emergence of some modern animals: new intelligent and beautiful animals - placental mammals, marsupials and birds began to conquer our planet.
Subclass Anapsid
Before the planet Earth began to be inhabited by different types of dinosaurs, many years passed aimed at the formation of the so-called genealogical tree of terrible dinosaurs. The most ancient and most primitive group is considered a subclass of anapsids. Immediately, we note that not one representative of this group has survived in one form or another to this day. The last anapsids became extinct about 200 million years ago. It happened in the Triassic period.
Subclass synapsid
The second evolutionary branch of future dinosaurs, the synapsid, separated from the root of the anapsids. This ancient class included the ancestors of mammals. But they were destined to sink into oblivion. So, unfortunately, and not seeing the heyday of their descendants - modern mammalian animals, to which we belong - people. It happened in the Jurassic period.
Subclass Diapsid
Much later, the synapsid from the base of the ancient trunk separated a new branch - diapsids. Its uniqueness lies in the fact that it is the subclass of diapsid that is divided into two more branches - archosaurs and lepidosaurs. Lepidosaurs are a group of animals that live on the Earth today: hatteria (ancient lizards), snakes, turtles. But not all lepidosaurs were able to survive to our era, among them there are known extinct forms, such as plesiosaurs - marine predators with long necks. According to legend, one such plesiosaur named Nessie still lives in the Scottish lake Loch Ness, but that's another story.
The branch of archosaurs was represented by crocodiles and other ancient reptiles, among them all kinds of flying dinosaurs, and land dinosaurs. Archosaurs are the most important lizards of all times and eras, one of the most diverse and amazing reptiles, the most perfect reptiles of the time. Fortunately, all dinosaurs became extinct, not having survived to our days, however, currently on the planet Earth there are several species of ancient crocodiles, preserved from those very times! What were these legendary dinosaurs? We bring to your attention the most striking species of dinosaurs and their description.
Loving diplodocus
This is a representative of a group of so-called sauropods. According to the calculations of paleontologists, these dinosaurs could reach a length of up to 58 meters with a weight of 113 tons. However, more and more modern scientists are inclined to believe that diplodocus did not exceed a length of 27 meters and a weight of 20 tons. The first fossils of this peace-lizard dinosaur were discovered by paleontologists in 1877 in the mountains of Colorado, USA.
Species of dinosaurs of this group lived in the late Jurassic period in the territory of modern North America about 150 million years ago. Paleontologists consider diplodocus one of the most easily recognizable dinosaurs. Moreover, this species is the largest of all dinosaurs known for its found complete skeletons. Diplodocus were herbivores, and their enormous size was a deterrent to predatory dinosaurs of those times - ceratosaurs and allosaurs.
Allosaurus is a thunderstorm of diplodocus!
In the framework of this article, we will not be able to consider all types of dinosaurs with names, so we turn only to the most striking and famous representatives of these legendary giants. One of them is the allosaurus. This is a representative of the genus of carnivorous dinosaurs from the theropod group. Like diplodocus, allosaurus existed in the Jurassic period about 155 million years ago.
These creatures moved on their hind legs and had very small forelimbs. On average, these lizards reached a length of 9 meters and a height of 4 meters. Allosaurus were considered large bipedal predators of the time. The remains of these insidious creatures were found on the territory of modern Southern Europe, East Africa and North America.
Ichthyosaurs - legendary fish hunters
They represent an extinct squad of large marine reptiles, reaching a length of 20 meters. Outwardly, these lizards resembled modern fish and dolphins. Their distinguishing feature was large eyes, protected by a bone ring. In general, at a short distance, ichthyosaurs could well be mistaken for fish or dolphins.
The origin of these creatures is still in question. Some paleontologists believe that they are natives of diapsids. This version is confirmed only by conjectures: apparently, the escape of ichthyosaurs somehow branched off from the main stem of the diapsid even before this subclass was divided into archosaurs and lepidosaurs. Nevertheless, the ancestors of these fish farmers are still not known. Ichthyosaurs became extinct about 90 million years ago.
Dinosaurs rise in the sky
At the end of the Triassic period, the first flying dinosaur species appeared on the planet, which unexpectedly appeared in the fossil record. It is curious that they were already fully formed. Their direct ancestors, from whom they developed all this time, are unknown.
All Triassic pterosaurs belong to the group of rumphorinchs: these creatures had huge heads, jagged mouths, long and narrow wings, a long and thin tail. The size of these "leather birds" varied. Pterosaurs - as they were called - possessed mainly the size of both gulls and hawks. Of course, among them were 5-meter giants. Pterosaurs became extinct about 65 million years ago.
Tyrannosaurs are the most famous dinosaur species.
The list of ancient dinosaurs would be incomplete if we did not mention the most magnificent dinosaur of all time and time - the tyrannosaurus. This insidious and dangerous creature fully justifies its name. This creature represents the genus of carnivorous dinosaurs from the group of coelurosaurs and theropod suborder. It includes one single species - the tyrannosaurus rex (from the Latin language “rex” is the king). Tyrannosaurs, like allosaurs, were two-legged predators with massive skulls and sharp teeth. The limbs of a tyrannosaurus represented a continuous physiological contradiction: massive hind legs and tiny hook-shaped forelegs.
The tyrannosaurus is the largest species within its own family, as well as one of the largest land predatory dinosaurs in the history of our planet. The remains of this animal were found in the west of modern North America. According to scientists, they lived about 65 million years ago, that is, it was precisely their century that the death of the entire dynasty of ancient dinosaurs occurred. It was tyrannosaurs that crowned the whole great era of dinosaurs, which ended during the Cretaceous period.
Feathered heritage
For many people, it is no secret that birds are direct descendants of dinosaurs. Paleontologists saw a lot in common in the external and internal structure of birds and dinosaurs. It should be remembered that birds are descendants of land dinosaurs - dinosaurs, and not flying dinosaurs - pterosaurs! Currently, two subclasses of ancient reptiles are "hanging in the air" because their ancestors and their exact origin have not been established by paleontologists. The first subclass is ichthyosaurs, and the second is turtles. If we have already dealt with ichthyosaurs above, then nothing is clear with turtles!
