Giant lizards may terrify you in movies, but are we exaggerating their presence in Earth’s history?
When we think of dinosaurs, we immediately picture massive, bloodthirsty reptiles and their dominance for over 150 million years.
This dramatic historical narrative is fundamentally incorrect in some aspects. Dinosaurs may not have been as fearsome as filmmakers portray.
The Origins of Dinosaurs Were Just Small Reptiles
Dinosaurs are believed to be the most dominant vertebrate group throughout the Jurassic period until the end of the Cretaceous period. But did they truly dominate the Earth as history suggests? (Photo: Getty).
The earliest known dinosaurs date back around 235 million years, from the mid-Triassic period.
Recent discoveries in Africa, South America, and Europe indicate that they were not much larger than a dog, being tall, slender, omnivores primarily feeding on leaves and beetles.
In contrast, their distant relatives, the crocodiles, were much more diverse and abundant. Among the crocodilian relatives in the Triassic period, there were carnivorous species with sharp teeth specifically adapted for hunting large prey on two legs.
They were covered in scales and bony spikes, with beaks resembling those of ostriches, and primarily fed on ferns.
Even as the first dinosaurs began to evolve into the dominant lineages that would flourish throughout the rest of the Mesozoic Era, most of them were small and less numerous than their crocodilian cousins.
Then, everything changed at the end of the Triassic period when severe volcanic eruptions altered the global climate, leading to the extinction of many other reptilian forms, allowing dinosaurs to gradually dominate.
If this mass extinction hadn’t occurred, we might have witnessed a “Age of Crocodiles” instead of the dinosaur age recorded in history.
Dinosaurs Never Evolved to Live in the Sea
The largest predators in the ocean during the Cretaceous period were reptiles and sharks, not dinosaurs. (Photo: De Agostini/Getty Images).
Three-quarters of our planet’s surface is ocean, and we cannot claim that dinosaurs dominated the Earth when their presence in the oceans was minimal.
While some dinosaur species evolved to swim and left traces in ancient shallow waters, history has never recorded any that evolved to live their entire lives in the ocean.
Even penguins—often dubbed “living dinosaurs”—have not developed the ability to remain at sea like many marine mammals and must return to land to breed.
Meanwhile, many non-dinosaur marine reptiles of various shapes and sizes dominated the underwater kingdom.
This small, diverse life form allowed marine reptiles to thrive for millions of years, despite climate changes and mass extinction events occurring on land.
Mammals Thrived During the Age of Dinosaurs
Mammals coexisted with dinosaurs at every stage of history. This indicates that dinosaurs may not have dominated the Earth in the way we perceive. (Photo: Getty).
Over the past two decades, paleontologists have rewritten the ancient story to demonstrate that mammals and our ancestors actually thrived alongside dinosaurs.
Ancient generations of squirrels, pandas, otters, beavers, and many others evolved through the Jurassic and Cretaceous periods, including primates living right “under the noses” of the fearsome Tyrannosaurus rex.
While it’s true that all known Mesozoic mammals were small, this does not necessarily indicate that they were inferior to dinosaurs.
In fact, researchers have identified that how our distant ancestors interacted with each other played a much more significant role in shaping the evolutionary process than dinosaurs did.
Even after the dinosaurs disappeared, most surviving mammal species continued to evolve with smaller sizes. This suggests that this was an evolutionary advantage for many mammal species, which dinosaurs inadvertently overlooked.
If they did not possess this finesse in their evolutionary journey, the question of whether dinosaurs truly dominated during their era remains a significant mystery.
