In Transformers: Age of Extinction an unidentified specie of brachiosaur was seen in the film. Here are some creatures it might have been.
Some believe it would have been Brachiosaurus a massive plant eating dinosaur. Despite this Brachiosaurus did not live in the end of the Mesozoic era. They lived in the middle of the era. Despite this, the animal looked a lot like a Brachiosaurus.
Another creature that it would have been is a Giraffatitan. It was related and similar to Brachiosaurus in size. Despite this it lived in the middle of the Mesozoic just like the very similar Brachiosaurus.
One error in the film was brachiosaurs never lived during the end of the age of dinosaurs. Also brachiosaurs couldn't run like in the film. Even the fastest which was Europasaurus can only run less than 10 mph.
The brachiosaurs were seen running with the hadrosaurs trying to ecape in time. All the brachiosaurs died though.
Some people can mistake the brachiosaurs as Brontosaurus a large plant eating dinosaur. Also in the earlier film Sludge was in brontosaurus but in the more recent one his mode is a Brachiosaur.