Did dinosaurs live in the Garden of Eden?
Dinosaurs and all the other animals – but not the great sea creatures or the birds – were created in the early morning of Friday, the sixth day of Earth's first week [Genesis 1:24-25]. The word "dinosaur" immediately brings to mind a fearsome T. rex or a mega-ton diplodocus, but those first created on the sixth day did not have to be full-sized. The dinosaurs were part of the reptile family, and fossil discoveries have shown that they hatched from eggs and were thus initially about the size of a kitten. Nevertheless, like every other created creature, they arrived with the appearance of age and need not have been larger than, say, a sheep-dog. As reptiles, they would have grown slowly and – unlike the ages of the pre-Flood patriarchs – could have lived over a thousand years. Some of those created on the sixth day may even have survived longer and died in the Genesis Flood.
Just an hour or so after the creation of the dinosaurs, Adam was created, necessarily with the appearance of age – say, about twelve years. Later that day, God took Adam and put him in the beautiful Garden of Eden to "tend and keep it" [Genesis 2:15]. Eve was seemingly made in the Garden of Eden perhaps a dozen hours after the creation of Adam as the very last of God's creation. Reasonably, she had the same apparent age as Adam. Living in this perfect environment, there was no danger to these children whose only duty was to learn from the very best teacher. Finally, since it is described as the "Garden" of Eden, we may tend to think of it being about the size of the average backyard, but the brief description given of it in Genesis 2:8-14 includes a major river sufficiently large to divide into four other rivers. The "Garden" was thus the size of a small country and likely had mountains as the source of all the water.
When Noah left the ark, he built an altar to the Lord. Then God blessed him and added: "And the fear of you and the dread of you shall be on every beast of the earth, on every bird of the air, on all that move on the earth and on all the fish of the sea. Every moving thing that lives shall be food for you" (Genesis 9:2-3). These words indicate that while Adam had been commanded to have dominion over the fish, the birds and the animals [Genesis 1:28], he had not been given permission to kill and eat them. Under these circumstances and certainly in the Garden of Eden, the animals were likely quite harmless to their human neighbors. In summary, then, it seems possible that there could well have been dinosaurs in the Garden of Eden, although they were likely small and friendly.