Why did animals grow so large during the dinosaur period but we see few enormous creatures today?”
The main one revolves around the climate of the Earth at that time. Some research suggests that it was much warmer and more conducive to life. With a bigger base, ecosystems could support larger and larger animals. These animals still had to compete with each other for territory and prey, and so the strongest won out more often than not. The bigger an animal is, the stronger it is, in general. With the abundance of life supporting it, competing predators kept evolving larger and larger to better able to compete. Our current earth supports land animals like elephants and giraffes, and sea animals like whales giant squid. An animal can only grow so large as their ecosystem can support. The ecosystem has to be able to support an entire herd or group of animals, and their prey, and the food sources of the prey. The lower temperature of the current age limits how quickly plant life grows, and so limits the food for prey for animals higher on the food chain. This is only a theory, and there
