Dinosaurs did not roam through rainforests. The iconic creatures lived in landscapes that were quite different from the dense jungles we often associate with them. In fact, it was the demise of the non-avian dinosaurs that paved the way for the formation of Earth’s first rainforests.
Contrary to popular depictions in movies like Jurassic Park, rainforests did not exist during the time of dinosaurs such as Tyrannosaurus and Triceratops. It was only after the catastrophic asteroid impact that ended the Cretaceous period that rainforests began to emerge. The absence of large dinosaurs and the rise of angiosperms, or flowering plants, created the ideal conditions for warm, humid forests to thrive.
The history of Earth’s rainforests was once shrouded in mystery due to a lack of fossil evidence. However, in 2009, researchers discovered the earliest known neotropical rainforest in Colombia, dating back approximately 58 million years. Fossils found in the Cerrejón Formation provided insights into the diverse plant life that existed in these ancient rainforests.
The presence of various plant species, predominantly angiosperms, indicated a forest environment similar to modern-day rainforests. The extinction of big dinosaurs like the T. rex played a crucial role in allowing rainforests to develop, as their presence would have prevented the dense canopy growth characteristic of these ecosystems.
The impact of the asteroid not only wiped out the dinosaurs but also altered the landscape and soil composition, favoring the growth of angiosperms. The enriched soil and increased nitrogen levels provided ideal conditions for these plants to flourish and form dense canopies. As a result, rainforests began to spread to regions far from the Equator, influencing the evolution of various species, including early primates.
The transition from open landscapes dominated by dinosaurs to closed-canopy rainforests opened up new ecological niches for organisms to diversify. The complex structure of rainforests created a wide range of habitats, driving the evolution of different behaviors and food preferences among species. This niche partitioning enhanced biodiversity compared to the more simplistic ecosystems of the Cretaceous period.
The accidental advantage that angiosperms gained following the mass extinction reshaped the planet and gave rise to the rich biodiversity we see in rainforests today. The evolution of these ecosystems was a direct consequence of the extinction event that ended the Age of Dinosaurs, highlighting the intricate relationship between environmental changes and the development of life on Earth.
