Could humans suddenly growing to the size of dinosaurs be as catastrophic as the asteroid that wiped out the prehistoric giants? Would it even be a world ending event? The answer depends entirely on which dinosaurs we are talking about. While most of us picture dinosaurs as colossal, fearsome creatures, many were surprisingly small.
The Tiny Threat: Microraptor Sized Humans
Take the Microraptor, for example. This dinosaur, found in China and dating back 125 million years, stood just 30 cm (1 foot) tall and weighed less than a kilogram (2 pounds) about the size of a Subway sandwich or a two liter soda. It had wings similar to a flying squirrels, allowing it to glide and snatch insects midair.
If humans shrank to this size, we would be roughly 18 percent of our current height. That might sound cute, but life would be incredibly inconvenient. Doors would be unreachable, cracks too narrow to escape, and emergency services would be useless.
You might only survive with three friends stacked in a trench coat.
Outside, the dangers escalate. Pigeons become deadly, and rats and cockroaches transform into apex predators. Fighting a rat would be like fighting a tiger. Even if humans somehow had gliding abilities like the Microraptor, fragile bones would mean frequent injuries upon landing. On the plus side, we would eat less, though not proportionally. Kleiber’s law tells us that smaller bodies require relatively more energy per kilogram, meaning we would need to snack almost constantly.
The Moderate Upgrade: Utahraptor Sized Humans
Now, let us scale humans up a bit. The Utahraptor, discovered in Utah, stood 1.8 meters (6 feet) tall and inspired Jurassic Parks Velociraptors. If humans matched this size, life would be mostly normal, except that social deception about height would vanish.
Humans would generally be healthier since taller people have slightly lower cardiovascular risks but only to a point. Daily life would still be manageable, and most infrastructure would accommodate this size. Overall, being Utahraptor sized might even be a minor improvement for some people’s health.
Large but Problematic: Triceratops Sized Humans
Consider the Triceratops, standing roughly 2.8 meters (9.2 feet) tall. At this height, we could reach any shelf without effort. But our hearts would struggle to pump blood efficiently, and our legs and lower back would bear an extra 130 kg (290 pounds), causing chronic joint pain. Homes would still fit us, but doorframes and ceilings would become hazards. At this size, crawling or moving on all fours might be more practical than standing upright.
The T rex Scenario: Big but Dumb
The Tyrannosaurus rex reached about 3.7 meters (12 feet) tall, a terrifying predator in its time. Humans of this size, however, would not be lethal. Our brains would grow proportionally, slowing signal transmission and reaction times. We would be essentially dumber in practice, unable to act fast enough to be effective predators.
Joint issues would worsen, making walking painful, and wheelchairs or leg braces might become necessary. The one upside? A deeper, more commanding voice perfect for narration.
The Sauroposeidon Nightmare: Humanity on a Colossal Scale
The largest known dinosaur, Sauroposeidon, soared to 18 meters (60 feet). At this scale, humans would trigger catastrophic destruction. Imagine eight billion people suddenly ten times our size. Cars, ceilings, and entire buildings would collapse under the immense weight each person would weigh over 80,000 kg (176,000 pounds).
Urban areas would face immediate structural failure, while suburban humans would struggle just to support their own bodies. Hearts would fail to pump blood effectively, leading to almost instant death. Evolution made humans well proportioned for life at our current size, so being 60 feet tall is literally impossible.
