Geologic Timeline Individual Reflection

There have been a lot of major events in Earth, but 3 stand out to me. The first event that stands out to me is the large extinction that occurred during the Permian era. This extinction wiped out many marine communities and created many niches, one of them being land, that helped the dinosaurs survive. This event is significant because if this extinction had not happen then Earth would've been still covered with marine life and would have barely any niche that would help us survive. The second one is the "Cambrian Explosion" that happened during the Cambrian Era. In this explosion, the diversification of life boosted throughout Earth, in a small amount of time, only about 40 million years. This explosion is significant because it resulted in new species and wide diversity. The third event that stands out to me is the mass extinction of the dinosaurs that occurred in the Mesozoic Era. The dinosaurs were all wiped out and this is significant because if they had not been wiped out, then humans would not have been able to dominate the food chain and perspire as we have, due to dinosaurs ultimately being the more powerful creatures when compared to humans and mammals.

The scale of Earth's history is massive, taking it a long time to grow into what it is now. Most of it is the Precambrian Era and about 542 million years ago was the Paleozoic Era, in which the oldest creatures existed. Also, about 251 million years ago, there was the Paleozoic Era, where the existence of many plants and animals started. There is also the Mesozoic Era, about 65.5 million years ago, and the Cenozoic Era, which is an ongoing era that started 65.5 million years ago. What surprised me is how recent Earth started developing and having life and diversity.

To us it seems like we've made a big impact on Earth with our technology and our creations but really we are just a very small part of Earth's history; we are merely a speck. Though we are just a speck, I feel as if we are a very important speck because of how we've used Earth's natural resources to our benefit to the point that we're ruining it (global warming, pollution, etc.). We are a little part of Earth's timeline but we have been impacting it a lot, changing it's natural flow with our creations. 

My question is what would Earth specifically been like if dinosaurs were still alive and haven't been wiped out?