Day 78: Dinosaurs

The Phanerozoic Eon. The Eon that has stretched across time for the last 538.8 million years, is the one we also find ourselves in right now. And it’s also where we can find dinosaurs.

In case you’re wondering, this is supposed to mark the beginning of the Cambrian Period. The Cambrian explosion or diversification or one of a dozen other names basically is a term used to indicate the beginning of the major divergences in the populations of animals we see today.

But the earliest dinosaurs only first appeared over 200 million years after the end of the Cambrian period. It’s crazy to think how little time has passed since their extinction when you think of the history of the planet, yes but so much more so when seen relative to the history of life itself. Crrrazy.

So yeah, they appeared about 245 - 233.3 mya, during the Triassic Period. And the major groups went extinct only about 66mya. And of course, the mass extinction event is what is responsible for this. This event is known as the K-Pg (Cretaceous-Paleogene) extinction event. And this time frame from 245 mya up until 65 mya is where I’m gonna focus, especially surrounding the K-Pg event - in order to answer my question, which was: “What was the environment/atmosphere like during the lifetimes of Dinosaurs and after the asteroid hit?”

Let’s see if they had crazy low atmospheric pressure or something.