Dinosaurs
The Most Well Known Prehistoric Creatures
Dinosaurs are archosaurs that first appeared around 230 million years ago and are still around today as birds. They have been popularized because of movies, in which they are portrayed inaccurately, making people think they looked and acted like monsters, or even label other reptiles that might not even be archosaurs (for example mosasauroids) as dinosaurs too. This website is made so the public will get a better understanding of dinosaur paleontology.
Family Tree
The Family Tree of dinosaurs
The Dinosauria is split in 2 orders: Saurischia ( "Lizard Hipped" ) And Ornithischia ( "Bird Hipped"). In the saurischia order there is the suborder theropoda and the suborder sauropodomorpha. In the theropoda there are all the ordinary bipedal dinosaurs such as Tyrannosaurus, Velociraptor and Spinosaurus, while there also are the modern day birds. In the sauropodomorpha there are the big-long-necked dinosaurs, like the brachiosaurus and the brontosaurus.
In the other hand we 've got the ornithischians, which include the marginocephalia, the thyreophora and the ornithopoda. The marginocephalia include dinosaurs like the triceratops, the pachycephalosaurus or the centrosaurus you can see above. The thyreophora include the stegosauria which have dinosaurs like the stegosaurus, and the ankylosauria which have dinosaurs like the anlylosaurus. And finally, the ornithopoda include dinosaurs like the iguanodon, the edmontosaurus and the corythosaurus.
Feathered Or Not?
Which Dinosaurs had and which hadn't feathers
You have possibly heard the news: most dinosaurs had feathers. But not all of them. All the feathered dinosaurs are theropods even though not all theropods have feathers either. So which dinosaurs had feathers and which not?
There is direct evidence of feathers on theropods, such as this fossil above. The specific group of theropods in which they appear is the coelurosauria, which include modern day birds, tyrannosauroids, ornithomimoids and compsognathoids. But still, most tyrannosaurs, such as the tyrannosaurus rex lacked feathers when they reached adulthood, even though they had them as juveniles.
But there is one group of dinosaurs that all of its members had feathers: the dromaiosaurs, which included the velociraptor, the deinonychus and more. So not only are the velociraptors from Jurassic Park much larger than the real ones but also lack feathers!
Not A Dinosaur
Creatures that are usually called dinosaurs but aren't
There are lots of prehistoric creatures that are not dinosaurs but sadly are labeled as. There is a chance that some of them are not even members of the archosauria, but rather members of the squamata (which includes lizards and snakes) or their own order (for example plesiosauria) So Here is a list of what actually these creatures are.
"Sea Dinosaurs"
Creatures such as plesiosaurs, mosasaurs or ichthyosaurs are often called marine dinosaurs, even though they aren't. They actually are marine reptiles, that have taken different evolutionary roads than the dinosaurs have.
"Flying Dinosaurs"
these creatures are actually related to the dinosaurs, since they are both ornithodirans and also evolved by the same common ancestor as them. However, they are still not dinosaurs. They are pterosaurs a group of reptiles that evolved powered flight.