Dinosaurs have been around for more than 230 million years!
About 250 million years ago, most life on earth went extinct, and within the next ten million years or so, dinosaurs began to evolve.
The exact timing of when dinosaurs first entered the scene is up for question, but we know for sure that it was between 230-245 million years ago.
Dinosaurs lived during the Mesozoic era.
The Mesozoic era roughly ran from 245 to 66 million years ago and is generally divided into three time periods: the Triassic, Jurassic, and Cretaceous periods.
Dinosaurs first evolved during the Triassic period, increased in number and variety in the Jurassic period, evolved even further during the Cretaceous period, and then, well, pretty much just died off really.
They evolved from reptiles the size of house cats.
From around 244 to 242 million years ago, small yet agile reptiles known as dinosauromorphs rapidly increased and spread across the world.
While they were far too small to come even close to the top of the food chain, they were speedy enough to escape predators for long enough to evolve into dinosaurs!
Dinosaurs are still alive and with us today!
Don’t go running and screaming for help, though, unless you happen to be deathly afraid of chickens!
In fact, all birds are descendants of dinosaurs – even the humble hummingbird.
All the non-avian dinosaurs went extinct, but the avian dinosaurs evolved over the millennia into birds.
Pterodactyls are not actually dinosaurs.
Pterodactyls, along with all other winged dinosaur-like reptiles, belong not to the dinosaur family but are classified as Pterosaurs.
While Pterosaurs are indeed related to dinosaurs, the connection is quite distant, splitting off from the archosaurs.
Dinosaurs are split into two main categories.
To put it simply, either a dinosaur is a saurischian (Greek for “lizard-hipped”), or they’re an ornithischian (Greek for “bird-hipped”).
Funnily enough, the lizard-hipped dinosaurs are more commonly related to modern-day birds, while the bird-hipped dinosaurs all went extinct!
The first dinosaur was named before we even knew dinosaurs existed.
In 1815 William Buckland, a geology professor from Oxford University, came across the skeleton of an animal unlike any previously recorded.
Deciding that it was some long-extinct form of reptile, he named it “Megalosaurus” (Greek for “great lizard”).
Dinosaurs were only classified in 1842.
Just seven years after Buckland discovered the megalosaurus, a geologist and his wife came upon a new iguana-like skeleton in Sussex, England, which they named “Iguanadon.”
More fossils started turning up, so Sir Richard Owen (who later founded London’s Natural History Museum) classified the fossils as belonging to the “Dinosauria” family (Greek for “terrible lizards”).
Dinosaurs weren’t named as such because they inspired terror.
When Sir Richard Owen came up with the name for dinosaurs, he meant the word terrible in a different sense.
He described them as being “fearfully great,” as in far larger in size than any previously known reptiles.
Maybe if the first fossil he came across were that of a T-rex, he would have meant it in more of a literal sense!
When the iguanodon was first reconstructed, its thumb was placed on top of its nose.
It wasn’t until 40 years later, in 1878, when more iguanodon skeletons were unearthed, that we realized the long, spiky thumb was not like a rhino’s horn but an odd thumb-like digit!
To this day, paleontologists still haven’t come up with a good reason why iguanodons developed such long spiky thumbs, although it may have been for self-defense.
