Scientists estimate that vertebrates inhabit our planet about 500 million years. 200 million. Of them in the domination of ancient reptiles called dinosaurs.At one time, the ancient reptiles were the crown of creation of mother nature, and their offshoot - the dinosaurs - all embody the pinnacle of every creeping thing that ever inhabited our planet.All kinds of dinosaurs, as well as their way of life in different periods succeeded each other, but the nature of their lives makes to the new adjustments.
Who are paleontologists?
Before we'll find out what are the kinds of dinosaurs that lived on our planet at different times, you need to know where it all started.The study of life, originate in distant era, it has been the science of paleontology.Its name comes from three Greek words: "Palaios" - an ancient, "Ontos" - being "Logos" - the word.People involved in this science, called paleontologists.Their work is a bit like detective work: by scattered fragments and human remains paleontologists need to restore whole image of bygone eras.A huge role in this is their intuition, combined with logic and imagination.
Even the most insignificant facts need careful study.Paleontologists collect them bit by bit.It's pretty tedious and exhausting work, because many events of the past are gone forever, not even leaving a single trace in the rocks.It is thanks to the efforts of these people, we can learn about what kind of animals once inhabited the planet Earth, what kinds of dinosaurs existed, what they looked like, how they lived, who were on the hunt, how to save on those or other hazards.Paleontologists have been able to recreate the picture bit by bit of the world of the great era of the dinosaurs.
how to shape the era of the dinosaurs?
course, all kinds of dinosaurs and species branching from them during the era of the great reptiles could not have become so numerous and widespread, if our planet did not develop and do not form properly.Age of Dinosaurs can be divided into several periods.Let us briefly consider each of them.
- Archaea.This is the first, the earliest period.It is a point of reference, from which originates the era of reptiles.At this time, the world is only beginning to arise life, was the evolution of single-celled organisms.
- Proterozoic.During this period, the planet began to appear multicellular animals and plants.
- Cambrian.The Cambrian life on Earth began to develop actively, appeared algae and aquatic invertebrates.
- Ordovician.It is that time is marked by the appearance of the first vertebrates on the planet beings.
- Silurian.In the Silurian period of invertebrates and some plant species are moving out of the water onto land.
- Devon.It is a time characterized by the appearance of gymnosperms, as well as animals such as amphibians, arachnids (spiders, mites), insects.
- Carbon.From here originates the era of the ancient reptiles.Reptiles, appeared in this period, divided into three branches: anapsid, Synapsid, Diapsid.At the same time the world began to emerge the first conifers and flying insects.
- Perm.Permian period marked the first appearance of the beetles, bugs, creatures Hymenoptera, the first small lizards and early archosaurs.
- Trias.Paleontologists have found that at this time our planet first began to inhabit the flies, while the last ancient amphibians - stegocephalia - became extinct.Endangered and representatives of the class anapsid.In the Triassic period were first crocodiles, turtles, flying reptiles, mammals and, of course, the dinosaurs.
- Jura.Jurassic - a kind of culmination of the age of dinosaurs.It was at this time on Earth appeared angiosperms, began flying butterfly, born some modern amphibians (the same green frog), any old bird (Archaeopteryx) and, of course, new species of dinosaurs.In the Jurassic period became extinct last representatives of a class Synapsid.
- Mel.Angiosperms finally conquered land.There were modern types of ants and mosquitoes.In addition, the Cretaceous period - this is the end of the great age of reptiles: at this time there was a complete extinction of the dinosaurs, marine reptiles, pterosaurs.It Cretaceous period marked by the appearance of some modern animals, our planet began to conquer new intelligent and beautiful animals - placental mammals, marsupials and birds.
Subclass anapsid
Before planet Earth began to settle different kinds of dinosaurs, it passed many years, aimed at the formation of the so-called genealogical tree terrible lizards.The most ancient and most primitive group is considered a subclass anapsid.Just note that no representative of that group did not live in one form or another to this day.Recent anapsid became extinct about 200 million. Years ago.It happened in the Triassic.
Subclass Synapsid
From the root anapsid separated the second branch of the evolutionary future of the dinosaurs - Synapsid.To this class belonged to the ancient ancestors of mammals.But he was destined to sink into oblivion.So, unfortunately, without seeing the prosperity of their descendants - modern mammals, which belongs to us - people.It happened in the Jurassic period.
Subclass Diapsid
Much later Synapsid from the base of the trunk of an ancient detached new branch - Diapsid.Its uniqueness lies in the fact that it is a subclass of Diapsid still divided into two branches - in the archosaurs and lepidosauria.Lepidosauria - a group of animals that live on the Earth and in our days: tuatara (ancient lizards), snakes, turtles.But not all lepidosauria able to live up to our time, some of them are known extinct forms such as plesiosaurs - marine predators with a bushy necks.According to the legend, the Scottish Loch Ness still lives one such plesiosaur named Nessie, but that's another story.
branch archosaurs were crocodiles and other ancient reptiles, including all kinds of flying dinosaurs, lizards and ground.Archosaurs - that's the most important dinosaurs of all time periods, some of the most diverse and amazing creatures of reptiles, the most advanced reptiles of the time.Fortunately, all the dinosaurs died out, and did not live up to the present day, however, currently on planet Earth live several species of ancient crocodile preserved ever time!What were these legendary dinosaurs?We bring you the most striking views of the dinosaurs and their description.
Peaceful Diplodocus
It is representative of a group of so-called sauropods.According to estimates of paleontologists, these dinosaurs could reach a length of 58 meters and weighs 113 tons.Increasingly, however, modern scholars are inclined to believe that Diplodocus not exceed the length of 27 meters and a weight of 20 tons.The first fossils of peaceful lizard was found by paleontologists in 1877 in the mountains of Colorado, USA.
dinosaur species in this group lived in the late Jurassic period in what is now North America about 150 million. Years ago.Paleontologists believe Diplodocus one of the most easily identifiable dinosaurs.Moreover, this species is the largest of all dinosaurs known from a complete skeleton found.Diplodocus were herbivores, and their huge size is a deterrent to predatory dinosaurs of the time - Allosaurus and Ceratosaurus.
Allosaurus - Diplodocus storm!
In this article, we will not be able to consider all kinds of dinosaurs with names, so just turn to the most prominent and well-known representatives of these legendary giants.One of them - Allosaurus.It is representative of the genus of carnivorous dinosaurs from the group of theropods.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 reptiles reached lengths of 9 meters and a height of 4 meters.Allosaurus is considered the largest bipedal predators that time.The remains of these insidious creatures have been found in what is now Southern Europe, East Africa and North America.
ichthyosaurs - the legendary fish-lizard
represent an extinct marine reptiles large squad, reaches a length of 20 meters.Externally, these dinosaurs were like modern fish and dolphins.A distinctive feature is their large eyes, protected by bony ring.In general, a short distance ichthyosaurs could well be mistaken for fish or dolphins.
origin of these creatures is still in question.Some paleontologists believe that they - came from Diapsid.This version is supported only guess: probably escape somehow ichthyosaurs branched from the main stem Diapsid before being divided into the subclass of archosaurs and lepidosauria.Nevertheless, the ancestors of these fish-lizard is still not known.Ichthyosaurs became extinct about 90 million. Years ago.
Dinosaurs rise into the sky
At the end of the Triassic period, the planet appeared first flying dinosaur species that have emerged in the fossil record suddenly.Curiously, they are already fully formed.Direct as their ancestors from which they evolved all the time, unknown.
include all the Triassic pterosaurs the group rhamphorhynchus: these creatures were huge head, toothed jaws and long, narrow wings, very long and thin tail.The size of these "birds of leather" varied.Pterosaurs - as they were called - had mainly sizes as the gulls and hawks.Of course, there were also 5-meter giants.Pterosaurs became extinct about 65 million years ago.
tyrannosaurs - the most famous dinosaur species
List of ancient dinosaurs would have been incomplete if we did not mention the magnificent dinosaur of all times and epochs - Tyrannosaurus rex.It is insidious and dangerous creature lives up to its name.This creature is born carnivorous dinosaurs from the group coelurosaurs and suborder theropods.It includes only one species - Tyrannosaurus Rex (from the Latin "Rex" - is king).Tyrannosaurus rex, Allosaurus as were bipedal predators with massive skulls and sharp teeth.Limbs Tyrannosaurus rex is a continuous physiological contradiction: massive hind legs and a tiny hook-like front paws.
Tyrannosaurus is the largest view within their own family, as well as one of the largest terrestrial carnivorous dinosaurs in the history of our planet.The remains of this animal have been found in western North America today.According to scientists, they lived about 65 million. Years ago, t. E. It was at their age came the death of the whole dynasty of ancient dinosaurs.It tyrannosaurs crowned a whole great era of the dinosaurs, which ended during the Cretaceous period.
feathered heritage
For many people it is no secret that the birds - are direct descendants of dinosaurs.Paleontologists have seen in the external and internal structure of birds and dinosaurs have much in common.Keep in mind that birds - are descendants of terrestrial dinosaurs - dinosaurs, not flying lizards - pterosaurs!Currently, two subclasses of the ancient reptiles, "hanging in the air", as their ancestors, and the exact origins are not established by paleontologists.First Division - is the ichthyosaurs and the second - turtles.If we have understood ichthyosaurs above, tortoise nothing at all clear!
Turtles - is an amphibian?
And so it is clear that, in considering a topic such as "Types of dinosaurs", not to mention about these animals.The origin of the Division of turtles are still shrouded in mystery.However, some zoologists still believe that they came from anapsid.However, they are opposed by other scholars, who believe that the turtle - the descendants of some ancient amphibians.It is not dependent on other reptiles.If this theory is confirmed, it will happen in the science of zoology major breakthrough: it may happen that a turtle does not have any relation to the reptile animals, because then they will ... amphibians!
