What is Dinosaurus?
Dinosaurs have been a group of Archosaurian reptiles who dominated the land for 160 million years, since the late Triasic period (230 million years ago) to the end of the Cretaceous (65 million years ago) when the meteor was erased. One row of dinosaurs, which survived, caused modern birds. The first dinosaur developed about 21 million years after the extinction of Permian-Triassic, which has erased most of the whole life. They were part of the first main wave of biodiversity, which followed this catastrophic event.
Dinosaurs are members of the superorder dinosauria , which also includes birds. Their closest relatives are pterosaurs, flying reptiles sometimes incorrectly called dinosaurs. Pterosaurs and dinosaurs are part of the unlimited advantage of archosaurs called ornithhodir . The only surviving archosaurs besides birds are order Crocodilia , including crocodiles, alligators, Gharials and Caimans.
Offici.ALly, dinosaurs are usually defined as all descendants withPolečný ancestor of Dinosaurs Triceratops and modern birds. This common predecessor lived in the late Triassical period., Dinosaurs include a huge group. Triceratops and modern birds were chosen because they are somewhat remotely relatives, so the descendants of their common ancestor are numerous and include all dinosaurs.
Definition based on morphology rather than phylogeny is "terrestrial archosauria reptiles with limbs that stood upright under the body". If the crocodiles were evolved to walk with the erect limbs under the body, they would suit this definition.
Dinosaurs are divided into two large groups depending on their hip structure: saurischides and ornithischides. These medium "lizards-shirts" and "bird-bolt". Dinosaurs with lizards include Theopods (mostly bipedal carnivores, including Tyrannosaurus Rex and Sauropodomorf (large, long neckor plants). The Bird-Hipped Dinosaurs Included Many Divers Herbivores, Including Hadrosaurids ("Duckbilled Dinosaurs"), Pachycephalosaurians ("Bone-Heads"), Ankylosaurians Stegosaurians (Armored Dinosaurs with Spiked Tails), Ceratopsians (Triceratops and Relatives), and Various Generic-Looking Types.
Dinosaurs ranged from the size of the chicken (Compsognathus) to the largest sauropods, which were 30 - 45 meters long (100 - 148 ft) and 60,000 - 100,000 kilograms (60 - 100 tons), if not more. The largest dinosaur he has ever discovered, Amphicoeelias Fragillimus, could reach a length of 60 m (200 ft), as long as a 20 -storey building, although it is based only on the descriptions of the femur and vertebrae that have decayed into dust since then. Bruhkayosaurus, another Sauropod, could weigh 220 tons, more than the blue whale, although there is a controversy about estimation.