My kiddo asked me this the other day. And well, the answer to that is yes. That’s right, dinosaurs do still exist, and they are everywhere – in the form of birds.
That adorable little sparrow on your windowsill? Dinosaur. The noisy cockatoo disturbing your morning coffee? Dinosaur. Pigeons, geese, hawks, you name it – they’re all descendants of large, two-legged, non-avian dinosaurs called theropods. Theropods, “whose members include the towering Tyrannosaurus rex and the smaller Velociraptors,” adapted certain existing dino features (such as feathers) into the birds we see today. Dinosaur extinction is just one myth scientists wish people would unlearn.
The word dinosaur comes from the Greek language and means ‘terrible lizard’. The word was coined by English paleontologist Richard Owen in 1842 and was meant to refer to Dinosaurs impressive size rather than their scary appearance. Dinosaurs ruled the Earth for over 160 million years, from the Triassic period around 230 million years ago through the Jurassic period and until the end of the Cretaceous period around 65 million years ago.
The time period from 250 million years ago until around 65 million years ago is known as the Mesozoic Era. It is often referred to as the Age of the Dinosaurs because most dinosaurs developed and became extinct during this time. It is believed that dinosaurs lived on Earth until around 65 million years ago when a mass extinction occurred.
Scientists believe that the event leading to the extinction may have been a massive asteroid impact or huge volcanic activity. Events such as these could have blocked out sunlight and significantly changed the Earth’s ecology.
Say that species-extinction asteroid hadn’t hit Mexico 66 million years ago and life on Earth had continued apace. Well-known dinosaurs like the Triceratops “would be totally different than anything we know from the fossil record,” science writer Brian Switek wrote in The Guardian. Why? They, too, would have continued to adapt. “There might even be new groups of dinosaurs that didn’t exist during the Mesozoic era.” But even extinct dinosaurs looked nothing like what most people believed when they were kids.
Why? It’s likely that, with dinosaurs remaining on our planet, humans and many other mammals would not have had the chance to evolve into existence. “Even though mammals thrived in the shadow of the dinosaurs, they did so at small sizes,” writes Switek. “And even though the very first primates had evolved by the end of the dinosaurian reign, they had more in common with a tree shrew than with you or me.”
The movie Jurassic Park took a lot of liberties with the possible, wrote biologist Ben Waggoner in Forbes. “Dilophosaurus, the critter that spits poison in Wayne Knight’s face, lived about 120 million years and 10,000 kilometres away from Velociraptor, the critters that ate Bob Peck.” So if all the extinct dinosaurs suddenly started roaming the Earth together at the same time … well, you’d have utter ecological chaos.
Plant eaters like Edmontosaurus, snacking on the diversity of flowering plants that exist today, would likely have gotten sick and perhaps even died. At the very least, wrote Waggoner, they might have just spent their whole lives hallucinating. The chemical makeup of modern plants isn’t anything like what dinosaur biology was meant to handle. More palatable plants might have been completely decimated by the hungry creatures.
All those dead and dying herbivores lying around – poisoned by flowering grasses and other plants their systems couldn’t handle – would have presented a total feeding bonanza for Tyrannosaurus rex, for example, and other partial scavengers, according to Forbes. Easy pickings!
That’s because the dead animals would run out. And when that happened, what would T. rex and friends eat? “There were mammals alive at the same time and place as T. rex, but none very big – and for all we know, modern mammal flesh might be unpalatable,” wrote Waggoner.
“An event known as the Paleocene-Eocene Thermal Maximum, 55 million years ago, saw average global temperatures reach eight degrees Celcius hotter than today’s temperatures, and rainforests spanning much of the planet,” according to BBC Future. “In this hothouse world with abundant vegetation, perhaps many longnecked sauropods might have grown more rapidly, breeding at a younger age and shrinking in size; several ‘dwarf’ sauropods (some little bigger than a cow) were already known in the late Cretaceous [era].”
Many modern birds have adapted to eating fruit and drinking the nectar of flowering plants – in fact, these things co-evolved so that birds would disperse the plants’ seeds. Some nonbird vegetarian dinosaurs could have developed this ability as well. Some or all may have grown into gradually smaller animals thanks to the relative ease of digestion of fruit and flowering plants compared to the gymnosperms (such as cycads and conifers) of the Cretaceous, palaeontologist Matt - Bonnan told BBC Future.
In the absence of dinosaurs, mammals slowly evolved with the ability to eat grassland plants. Vertebrate paleontologist Darren Naish speculated that surviving dinosaurs would have evolved much quicker thanks to evolutionary advantages they’d already developed, like the 1000 teeth that hadrosaurs had in their jaws, which would have been extremely well-suited to grinding grass.
Physical changes to the heads and bodies of these grass munchers would eventually have evolved. As BBC Future pointed out, “Horses and cows have flattened muzzles useful for cropping tough, low-lying vegetation.” Grass-eating, duck-billed dinosaurs might have developed squaredoff snouts, and “sauropod necks might have shortened to aid grazing at their feet.”
As a bonus, here’s my top five list of funny facts:
- A dinosaur called the Pegomastax is one of the weirdest dinosaurs known. Described as a cross between a parrot and porcupine, it had a beak with teeth that sharpened themselves against each other.
- In the 1993 movie, Jurassic Park, there is only 15 minutes of dinosaur footage: 6 minutes of CGI and 9 minutes of animatronics.
- One of the weirdest dinosaurs is the Suzhousaurus. Looking like a giant rat, this odd dinosaur also had a furry body, which suggests it is a distant ancestor of the giant ground sloth.
- People have only been on Earth about 2.5 million years. Dinosaurs lived on Earth for about 160 million years, which is about 64 times longer than people been around.
- The name “Velociraptor” means speedy thief.
Finally go check out this dinosaur museum in Dorchester! Cool stuff!
Check out my related post: What is the Silurian Hypothesis?