I'm doing this story a little earlier than I planed but here you go. But before you read this look up the Dinobots and Autobots from TF4, TF Fall of Cybertron, and TF RID (2013). These are pre-chapters.

On the founding of a number of Dragon islands where Vikinga land, & see countless dragons,in the year 1256 B.C. Optimus Prime: "Earth, birth place of the human race and the dragon race. Two species much like our own. Capable of great compassion. And great violence. For in our quest to protect the humans and dragons a deeper revaluation dawns: our worlds have met before."

Before the dragons and Vikings could start their battles they saw something coming from the sky and as what looks like a ship hovering in the air and see Giant metal, Warriors, the leader with a sword swathe humans and dragons he goes to see them.

The Vikings ready their weapons and the dragons ready to fire the metal Giant was over 110FT tall, as carefully walks without stepping on either humans or dragons, he picks up a Viking and a Gronckle, to see these creatures.

Soon all the metal Giants look around and found fossil remains of a T-Rex, Spinosaurs, Triceratops, a Pterandon, Velociraptor, Apatosaurus, Stegosaurus and Brontasorus. They scan the remains and the leader transforms into a metal horned T-Rex.