"Dynosaurs and their decendents have been on the earth for over 300 MILLION YEARS. Man in his present form has been on this earth for only 10,000-20,000 years. Put in perspective, if 300 million years were 24 hours then 1 second would be equal to 3472 years. So while dynosaurs and their decendents have made it through 24 hours, modern humans have been around for the past 2.9 to 5.8 SECONDS!"
This part of your post is true, except for Man being around for 10-20,000 years - it is estimated that we've been around for about 100-150,000 years.
But anyways, the fossil records show us that the first life on Earth was aquatic. Animals that lived on the land came later, about 400 million years ago. Then, dinosaurs gradually (gradually over a hundred million years or so) came into existence. Man is the most recent species to have "arrived on the scene". Keep that in mind when you read this excerpt from Genesis...
1:20
And God said, Let the waters bring forth abundantly the moving creature that hath life, and fowl that may fly above the earth in the open firmament of heaven.
1:21
And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his kind: and God saw that it was good.
1:22
And God blessed them, saying, Be fruitful, and multiply, and fill the waters in the seas, and let fowl multiply in the earth.
1:23
And the evening and the morning were the fifth day.
1:24
And God said, Let the earth bring forth the living creature after his kind, cattle, and creeping thing, and beast of the earth after his kind: and it was so.
1:25
And God made the beast of the earth after his kind, and cattle after their kind, and every thing that creepeth upon the earth after his kind: and God saw that it was good.
1:26
And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth.
1:27
So God created man in his own image, in the image of God created he him; male and female created he them.
1:28
And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth.
Don't let the whole "seven days" thing be a stumbling block. God is beyond time. Read Einstein's Theory of Relativity. We have no idea what the fuck "time" is.