Here is my point of view.
Before day 1 god had already created heaven and Earth.
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The Beginning
1 In the beginning God created the heavens and the earth. 2 Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters.
Before those days from 1-7,.Earth existed in a form different than we know now and a different atmosphere. He doesn't say it was non existent because it scripture says "his spirit was hovering over the waters
" .So during those times I am assuming dinosaurs existed for a while and god caused the Mass extinction of it because he was unhappy with all the darkness in the so called Earth. Now dinosaurs are not in the scriptures but I am assuming from the timeline and explanations of science.
After those days of darkness he began the process of reforming the Earth as we now know which is explained in days 1-7.[/QUOTE]
Entirely possible. Before God started the process of creation as stated in the book of Genesis it states that the earth was formless and empty. What it does not state is that it was always formless and empty. Very interesting perception on your part worthy of consideration.