Here is a Reasoning I made before
The fact that people make pictures of dragons, monsters, spaceships and other things doesn't necessarily mean they ever saw one.
Look at all the artists in the world, from paintings, sculptures, movies and other mediums and how they make creatures and other things that have never been seen before.
I am not saying that the people in old times didn't see dragons or monsters, but the fact that they made a picture of one doesn't at all mean they actually saw one. Humans have a great capacity for imagination. So no conclusion can be made either way based on paintings, sculptures and other similar things.
If you look at Genesis and compare it to Evolution theory, the order of things are very similar.
 In the beginning God created the heaven and the earth.
Evolution theory speaks of the beginning of matter and space
 And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
 And God said, Let there be light: and there was light.
 And God saw the light, that it was good: and God divided the light from the darkness.
 And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day.
This seems to suggest that the light came after matter was formed, this part differs from evolution theory. I think evolution theory speaks of the light coming first.
 And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters.
 And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so.
 And God called the firmament Heaven. And the evening and the morning were the second day.
Evolution theory speaks of the atmosphere forming around the time the waters formed.
 And God said, Let the waters under the heaven be gathered together unto one place, and let the dry land appear: and it was so.
 And God called the dry land Earth; and the gathering together of the waters called he Seas: and God saw that it was good.
Evolution theory says that the earth was first covered with water and one of the many theories say that at some point a lot of the water boiled away (I think from meteors and other things from space falling to the earth) and uncovered the earth. They claim that there might have been life in the waters before this but they also claim that all that life died when the waters boiled, which makes it possible that no living cell-based organisms existed before this point.
 And God said, Let the earth bring forth grass, the herb yielding seed, and the fruit tree yielding fruit after his kind, whose seed is in itself, upon the earth: and it was so.
 And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind: and God saw that it was good.
 And the evening and the morning were the third day.
Evolution theory says that the plants appeared on earth before animals.
 And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years:
 And let them be for lights in the firmament of the heaven to give light upon the earth: and it was so.
 And God made two great lights; the greater light to rule the day, and the lesser light to rule the night: he made the stars also.
 And God set them in the firmament of the heaven to give light upon the earth,
 And to rule over the day and over the night, and to divide the light from the darkness: and God saw that it was good.
 And the evening and the morning were the fourth day.
The order of this is not the same as evolution theory, it would say that the sun and stars came first.
 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.
 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.
 And God blessed them, saying, Be fruitful, and multiply, and fill the waters in the seas, and let fowl multiply in the earth.
 And the evening and the morning were the fifth day.
 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.
 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.
Evolution theory also speaks of all the animals coming some time after plants were formed. And just as evolution theory speaks of animals coming first in the ocean Genesis 1:20 shows the same thing.
 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.
 So God created man in his own image, in the image of God created he him; male and female created he them.
 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.
Evolution theory also speaks of man coming into being after many of the other animals were formed.
Evolution theory is just that, a theory. The differences between the order of things in Genesis and the order of things in evolution theory could be a mistake in evolution theory or genesis, I can't say for sure.
But if you look at the overall picture, both sequences of events are very similar.
Jah RasTafarI Haile Selassie I formed all things.
You said that dinosaurs weren't specifically mentioned, but almost all animals were not specifically mentioned in Genesis, only a few were mentioned by name, the rest were generally refered to as creatures.
However everything came about, Jah RasTafarI must have had a great part, how else could such an amazing system of Life be formed, which always returns to balance.