In the first Transformers movie it was revealed that the US government had known of the existence of the living machines at least since 1897, when Archibald Witwicky discovered the frozen remains of the Decepticon leader Megatron, frozen in ice in the Arctic Circle. Then, in the second Transformers movie, Revenge of the Fallen it was revealed that a Prime had arrived on Earth in 17,000 BC in an attempt to harvest our sun for its energy, having broken Prime law (no sun supporting life should be harvested) the Fallen Prime was stopped and imprisoned by the other Primes. And, once again in the third Transformers movie Dark of the Moon, it was revealed that mankinds famous first landing on the moon was in actual fact to investigate a crashed Transformer vehicle known as the Ark. This theme of pre-visitation seems to be popular with Michael Bay, and presumably it seems it will be used again in the forthcoming fourth movie; Age of Extinction, with a band of Transformers having landed on Earth during the age of the Dinosaurs - the Dinobots.
As the following concept art pieces from Hasbro license holder Vilsco Textiles shows, it turns out pre-production for Transformers: Age of Extinction began shortly after Dark of the Moon was released. First we have the Autobots Optimus Prime, Bumblebee, Hound and Drift, as well as the car-modes for the Autobots...
...Then we have concept art of the Decepticon Lockdown, seen in the trailer transforming his head into a huge cannon, as well as some vehicle modes for the Decepticons...
...And concept showing one of the Dinobots also featured in the trailer - Grimlock...
In this plethora of images from Vilsco Textiles is also a release schedule, which shows that Transformers 5 is set for release in 2017, though we hope that the proposed logo is changed by then, maybe using the roman numeral V.
