After the dinosaurs went extinct, why didn’t new giant animals come to be?
In: Biology
When the first dinosaurs evolved to big creatures the world was very different then it is today. There were a single big continent allowing the big creatures a large area to find food. We still see this today with smaller isolated islands having developed smaller animals then on the main continent. The oxygen level in the atmosphere was also much higher then it currently is making it easier to get enough oxygen to all the muscles. There were also generally very few types of plants and animals around so that animals specializing in one food could dominate the food chain and eliminate any competitors. However at the end of the dinosaur eras the world was much more similar to how it is now. The continents had broken up into their current shapes, oxygen levels were down to the same levels where they are now and there were a lot more plants and animals around like grass, flowers, mice, etc. so that smaller animals had a much easier time finding their niche. These changes likely contributed more to the extinction of dinosaures then any natural disaster.
But that does not mean that there have not been giant animals since the dinosaurus. There are several species of mammals roming the Earth that is larger then most dinosaurus. It used to be a lot more but then humans started hunting them. Movies such as Jurasic Park does not give a realistic picture of how big dinosaurus were. They mostly depict the biggest dinosaurs and even then a lot of them is blown out of proportion. Even museums with dinosaur exhibits usually display larger species much more promenently then smaller species if they display smaller species at all. Most dinosaurs were between the size of a dog and human. And this is the range of sizes you expect for mammals today.
Latest Answers