The dinosaur was laid out and strapped to a flatbed truck, partially covered by blood-soaked sheets.
It was driven through the streets of London from 7am yesterday morning, taking a tour through Brixton, central London and past the Houses of Parliament, Trafalgar Square, London Bridge and Buckingham Palace.
Social media users, as well as Transport for London (TfL), tweeted the passing dinosaur and speculated what the deceased creature could be in aid of.
National Geographic later revealed itself to be the brand behind the stunt.
Sketch Events worked with the channel to create the experiential activity, which was supported from a PR perspective by Premier Communications.
Ed Sayer, vice president of commissioning at National Geographic Channels International, said: "We are thrilled to be unveiling T. Rex Autopsy to British audiences this Sunday (7 June) - a one-off special event featuring the world’s first full-size, anatomically complete recreation of a Tyrannosaurus Rex, made in line with the latest paleontological discoveries.
"To mark this occasion and the start of Jurassic Week on National Geographic Channel, a replica T. Rex hit the streets of London to give the public a taster of what is to come."
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