On the 5th day.
Genesis 1:20-25
20 Then God said, “Let the waters abound with an abundance of living 5creatures, and let birds fly above the earth across the face of the 6firmament of the heavens.” 21 So God created great sea creatures and every living thing that moves, with which the waters abounded, according to their kind, and every winged bird according to its kind. And God saw that it was good. 22 And God blessed them, saying, x“Be fruitful and multiply, and fill the waters in the seas, and let birds multiply on the earth.” 23 So the evening and the morning were the fifth day.
24 Then God said, “Let the earth bring forth the living creature according to its kind: cattle and creeping thing and beast of the earth, each according to its kind”; and it was so. 25 And God made the beast of the earth according to its kind, cattle according to its kind, and everything that creeps on the earth according to its kind. And God saw that it was good.
23 So the evening and the morning were the fifth day.
On the 6th day
Genesis 1:26
26 Then God said, “Let Us make man in Our image, according to Our likeness; let them have dominion over the fish of the sea, over the birds of the air, and over the cattle, over all the earth and over every creeping thing that creeps on the earth.”
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The Bible does not say that there were "millions" of years between the two events.
Did God create a super animal millions of years before man? and how much time was in between the 5th and 6th day?
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Job 38:4
4 “Where were you when I laid the foundations of the earth?
Tell Me, if you have understanding.
That is what the Bible teaches. The existence of dinosaurs "millions" of years ago or millions of years before man is not proven Biblically.