What did the earth look like when the dinosaurs lived?

Answer

Dear Danny

Volcanoes have been around as long as the earth has existed. When the solar system came into being, 4.57 billion years ago, the earth was still completely melted. However, ever since the Earth’s surface solidified and the first crust formed, magma kept bubbling up from the deep and has continued to do so ever since. Many dinosaurs will therefore also have had to do with volcanoes and their consequences.

In the time of the dinosaurs (between the Middle Triassic and Late Cretaceous, 242 to 66 million years ago) there were initially mainly gymnosperms in the form of trees and low vegetation. Flower-bearing plants and trees only became numerous and diverse during the Cretaceous period. In a correct reconstruction you will not see herds of herbivorous dinosaurs (eg Triceratops or Iguanodon) moving through vast grasslands. Such biotopes only became common during the Miocene, about 15 million years ago.

How do we know all this? We can infer this from the pollen of plants that are found along with the bones of the dinosaurs in the sedimentary rocks that formed in wetlands when the organisms lived. With a detailed analysis of the rock, we can thus approximately reconstruct the environment and composition of an ecosystem. The pictures you refer to are an artistic representation of all that information. If we also find layers of volcanic ash in those rocks, then we know that there must have been a volcano nearby.

Finally, the Archosaur clade is a group of related fossil and recent organisms that form a lineage in reptiles (and birds). In addition to the dinosaurs, the group also contains crocodiles and all birds, the modern descendants of the dinosaurs.