Did Humans Live Alongside Dinosaurs? 6 Curious Facts
Humans never overlapped with the great dinosaurs, but we do live alongside dinosaurs: birds, including the chicken. We go over six curious facts and explain why some species survived the asteroid and others did not.
Humans and the great dinosaurs never overlapped
The great dinosaurs disappeared 66 million years ago. The oldest fossils of our species, found at Jebel Irhoud (Morocco), are around 300,000 years old.
If the entire history of the Earth were squeezed into a single day, the dinosaurs would go extinct about twenty-one minutes before midnight. Humans would appear in the last six seconds.
T. rex lived closer to us than to Stegosaurus
Stegosaurus lived about 150 million years ago in what is now Colorado. T. rex appeared about 68 million years ago.
More than 80 million years separate the two. Between T. rex and us, 66. Something similar happens with Cleopatra: she lived closer to the Moon landing than to the construction of the Great Pyramid.
Pterodactyls and marine reptiles are not dinosaurs
The pterodactyl is a pterosaur. It is a close relative of the dinosaurs, but from a different family. Its wing was a membrane of skin stretched from a single, greatly elongated finger: the fourth.
Some were enormous. Quetzalcoatlus, from Texas, had a wingspan of around ten meters, like a light aircraft. Standing up, it reached the height of a giraffe.
The great marine reptiles were not dinosaurs either. Mosasaurs, for example, were related to lizards and snakes.
Velociraptor had feathers
In 2007, researchers at the American Museum of Natural History studied a Velociraptor forearm found in Mongolia. Along the ulna was a row of small bumps: the attachment points for the long wing feathers, the same as those found in many modern birds.
The feathers were not preserved, but their attachment points were. What's more, the real Velociraptor was the size of a turkey and weighed about fifteen kilos. The raptors in Jurassic Park were mainly inspired by Deinonychus, a much larger North American species.
Birds don't descend from dinosaurs: they are dinosaurs
A bat is a mammal even though it flies. In the same way, a pigeon is a theropod dinosaur, from the same branch as T. rex and Velociraptor.
The first clue turned up in 1861 in a quarry at Solnhofen (Germany): Archaeopteryx, with feathers, teeth and a long, bony tail. More evidence followed: hollow bones, the wishbone in tyrannosaurs, and a Citipati fossilized in Mongolia on top of its nest, arms spread over the eggs like a brooding hen.
That is why today we share the planet with some eleven thousand species of dinosaur.
Why the chicken survived and T. rex didn't
An asteroid about ten kilometers wide struck Chicxulub, on the Yucatán Peninsula. In 1980, Luis and Walter Alvarez, father and son, published the key clue: a thin layer of clay at Gubbio (Italy) loaded with iridium, a metal that is rare in the Earth's crust and abundant in asteroids. That layer also appears in Spain, at Caravaca de la Cruz and in the cliffs of Zumaia. The crater, about 180 kilometers across, was later located beneath Mexico.
The Deccan volcanoes in India were already disrupting the climate. Even so, most experts attribute the final blow to the impact.
Most species were not killed by the collision itself, but by what came after. The asteroid struck rocks rich in sulfur and hydrocarbons. It threw up soot and aerosols that darkened the sky for years. Without light, photosynthesis collapsed. Without plants, the herbivores fell. Without herbivores, the carnivores followed. About three out of every four species disappeared.
A 2017 Japanese study calculated that only around thirteen percent of the planet's surface had enough hydrocarbons to trigger that winter. If it is correct, the location of the impact was also decisive.
The survivors were mostly small, ground-dwelling birds with beaks capable of eating seeds. Seeds held out underground when the forests collapsed. A small animal needed only a few. A T. rex weighing about eight tonnes needed large prey, and there was none left.
Frequently asked questions
Did humans live alongside dinosaurs?
Not with the great dinosaurs: they disappeared 66 million years ago, and our species is about 300,000 years old. But we do live alongside dinosaurs, because birds are dinosaurs.
Is the pterodactyl a dinosaur?
No. It is a pterosaur, a close relative of the dinosaurs but from a different family.
Did Velociraptor have feathers?
Yes. A forearm found in Mongolia and studied in 2007 preserves the attachment points for the wing feathers on the ulna.
Why did birds survive the asteroid?
The survivors were mostly small, ground-dwelling birds able to eat seeds, which held out underground when the sky went dark. Large predators such as T. rex were left without prey.
Informative article written with the help of AI tools from the verified script of the video. The video is in Spanish.