Answer: We know that dinosaurs existed because there is a significant amount of evidence that they did in the fossil record. One frequent question that people have is where chronologically do they fit in. If man has existed for only a relatively short time period then how do we explain the long ages that science has assigned to these animals? Did the earliest known dinosaurs begin to appear in the Triassic period some 245 million years ago?
The typical answer to the question of when dinosaurs were made are, most times, based on misconceptions concerning the chronology as outlined in the scriptures. A common misconception is that everything that was created was made when man was formed.
The Bible reveals that there was a creation prior to Adam and Eve. Even though Man was made on the sixth day of creation he was NOT the first living organism to be created! Dinosaurs almost certainly existed prior to the first human.
Although man is only a few thousand years old, the earth itself is much older. We are not sure, however, how much older because the Bible simply does not give us that type of information. The first chapter of Genesis is not an initial creation story, but a RE-creation of things that already existed. This allows for the possibility that dinosaurs may have been brought back into existence.
The Hebrew word (Strong's Concordance #H1961) from which we get the English word "was" in Genesis 1:2 should be translated as "'had become." The earth HAD BECOME (sometime after initial creation) without form and void due to Lucifer's rebellion. An example of the same Hebrew word used in Genesis 1:1 - 2 but rendered in the NKJV, NIV and other translations as "became" or "had become," can be found in the seventh verse of Genesis chapter 2.
The first two verses of Genesis 1 reveal that the earth was created with various forms of life, including dinosaurs, and then became a cosmic wasteland. After this occurred we find the earth was covered in a deep mantle of water. All life that had been originally created became extinct, including giant reptiles and dinosaurs. The earth was, as the scripture says, "without form and void." Then God recreated and refashioned the earth to support human life.
Although the Bible does not state the time span between the first two verses of Genesis 1, the earth does not necessarily have to be extremely old (and certainly was old enough to support dinosaurs).
Long spans of time are generally used by those who wish to support evolution. Since evolution is not correct, large chunks of time are simply not necessary. Man's best dating methods are really only guesses since they are based on assumptions that do not take into account how earth's chaotic past has skewed their 'evidence.'
God made the dinosaurs well before He made Adam and Eve. Sometime after he made them the world became a convulsing and chaotic mess due to Satan's war against the Eternal (Revelation 12:7).
When the Eternal re-created all things (Genesis 1, 2) he likely brought back these large reptiles or dinosaurs. Evidence suggests that possibly some of these huge beasts lived for a time after Noah's flood.