Sebastian Kopp, Grade 9, Staff Writer
Dinosaurs. Potentially the most famous and adored group of animals to ever exist. Two hundred years ago, on February 20, 1824, a dinosaur was written up in the scientific literature for the first time. It is known as Megalosaurus bucklandii. Megalosaurus was a 20-foot long, 1,500 pound carnivore. The original specimen was a piece of the right lower jaw found in Stonesfield, Oxfordshire. British paleontologist Darren Naish once wrote, “Why... are dinosaurs popular? Because they look neat, because they’re awesome in every sense of the word, because they ruled a vast, chaotic, complex wilderness, and because they’re the source of a myriad of big, really interesting questions.” Dinosaurs** were majestic and powerful animals that dominated a world so far back in the past that it’s almost impossible to comprehend.
To put it in perspective, two dinosaurs often seen fighting in popular media are Stegosaurus and Tyrannosaurus. Tyrannosaurus lived closer to us than it did to Stegosaurus, and Stegosaurus showed up halfway through the Mesozoic (the time of the dinosaurs). They persisted through two mass extinction events and rose to the top of the food chain. They occupied every continent and came in all shapes and sizes. We now know of over 1000 distinct species, with a new one being discovered on average once a week. According to recent estimates, we haven’t even discovered 30% of the fossilized dinosaurs on our planet. And judging by the fact that we know of around 10000 distinct species of birds, there must be a lot out there. On top of this, since 85 to 97% of organisms don’t fossilize, we will never know anywhere near the amount of dinosaurs that lived during the Mesozoic era.
As much as I would love to go into detail about the families of the dinosaur phylogenetic tree, that would take up too much space. Instead, I’ll simplify it. The dinosaurs are split into two main groups: Saurischia (lizard- hipped) and Ornithischia (bird-hipped). The Ornithischian dinosaurs include most groups of herbivores. Thyreophoran (Ankylosaurus and Stegosaurus), ceratopsian (Triceratops and Styracosaurus), and ornithopod (Iguanodon and Parasaurolophus) dinosaurs are members of Ornithischia. Saurischia contains groups such as the theropods (Tyrannosaurus and Velociraptor) and the sauropodomorphs (Brachiosaurus and Diplodocus). Theropoda, on its own, contains many different groups, the most famous of which being Ceratosauria (Ceratosaurus and Carnotaurus), Megalosauroidea (Megalosaurus and Spinosaurus), and Coelurosauria (Tyrannosaurus and Corvus). If you know ornithology, you will understand that Corvus is the genus name for the crow. A common misconception is that birds are related to dinosaurs when, in actuality, they are dinosaurs. That's right. If you look out your window and see a pigeon pecking crumbs from the ground, you are looking at a living, breathing dinosaur.
On the topic of misconceptions, I can’t think of any group more riddled with them than dinosaurs. While they may be the most famous group of animals, they are also probably the most misunderstood. I will do my best to correct some of the more common misconceptions. Contrary to popular belief, there were no flying dinosaurs. Now, I know you’re thinking, ‘But what about Pterodactyl?’ Pterodactyl is not a real thing. The word ‘Pterodactyl’ is usually used to refer to Pterosauria, an extinct order of reptiles that lived simultaneously as the dinosaurs. It’s an understandable misconception, as they are both reptiles and both lived at the same time. Another misconception is that dinosaurs are lizards. Dinosaurs are part of a family called Archosauria (ruling reptiles). Lizards come from a different, though similar, family called Lepidosauria (scaled lizards). Another fun fact is that, unlike most living reptiles, dinosaurs were endothermic (warm-blooded). While popular media likes to display massive and intimidating animals, most dinosaurs were on the smaller side. If any of this information is helpful, I’m glad. I hope that you enjoyed learning as much about these majestic creatures as I do.
Photo Credits: Dr. Mark Witton