If we give up the notion that a day back then is exactly like a day now--24 hours--you can see that we don't have a set time for the creation story in Genesis.  It could have taken a long long time.  Peter, the apostle, gives us a clue when he says in 2 Peter 3:8-9: "...do not forget this one thing, dear friends: With the Lord a day is like a thousand years and a thousand years are like a day."

In whatever "time span" this series of events happened, once everything was in place, things on earth begin to grow.  An interesting comment about this is in Genesis 1:11-12,  "Let the earth bring forth grass...and the fruit tree yielding fruit after his kind whose seed is in itself, upon the earth...and the earth brought forth grass...whose seed is in itself upon the earth.

Does "letting"this happen mean that "pockets of dryness" held seed on the earth from when God created plant life in those dinosauric times?  I don't know, but seed will grow after very long periods of time if kept in dry pockets.  I have okra seed from over ten years ago that sprouts when I plant it.  I heard that scientists planted corn seed from Pharaoh's tomb and it grew.  Whether God used seed caught in dry pockets on land, or He started over, is not clear.  Either way works scientifically.

Now it gets interesting.  Genesis 1:14, "Let there be lights in the heaven...let them be for signs and for seasons and for days and years.  And let...them give light upon the earth.  And God made two great lights..to rule the day and the lesser light to rule the night.  He made the stars also. He had previously created them.  He takes something already there--and lets something happen.  Is matter gathering up into a sun? Is the earth spinning so fast the moon breaks away from the earth? (Science tells us that the substance of the moon came from earth.)  Is God flinging stars off into the universe?

I don't know how long this took, or how He did it.  God doesn't tell us much about what went on before we were created.  Is this about the earth rotating around the sun?  Or is it about the earth rotating on it's axis?  In Genesis 1:3, God already said, "Let there be light."     Whichever way it is, God is getting ready for His second creative act.  The world is ready for mammals.  We have seen a huge gap between the dinosaurs and this moment.  And if you read Genesis to find out what it is actually  saying instead of what you have assumed, you can see that there is no error scientifically.