Science journalist Mr Hanlon, who came up with the plans for dinosaur museum Jurassica, died on Tuesday aged 51 after a heart attack.
The museum was to be built in a semi-subterranean artificial cavern in a 40m (132ft) deep quarry in Portland.
The project's trustees said they hoped to carry it on "in some shape or form".
There are plans for robotic swimming plesiosaurs in an aquarium, fossils and interactive displays.
Mr Hanlon had attended a Jurassica board meeting just before he was taken ill.
Richard Edmonds, Jurassic Coast earth science manager, said: "He was the driving force behind this amazing project - we're all reeling with the loss.
"Without his enthusiasm and leadership it's going to be harder still, but the coast needs something like this.
"I'm sure we will get there in some shape or form."
Sam Rose, Jurassic Coast World Heritage Site manager, said: "We hope that Michael's dream and vision lives on.
"His energy and commitment to bring the stories of the Jurassic Coast alive to a huge audience will be sorely missed."
The project has Sir David Attenborough as its patron.
In tribute, Sir David said: "Michael was a great visionary with a wonderful idea to bring the past to life, an idea without parallel."
Sir Tim Smit, co-founder of the Eden Project and a trustee of Jurassica, said: "He had a dream to create something really special.
"I joined him in the journey - as did so many others who had excuses not to get involved, but did - because we felt he was right and the work was something of which Britain would be rightly proud."
The project, which gained charitable status in 2014, was turned down for £16m of Heritage Lottery funding in May.
It is being funded through sponsors and grants.
Previously organisers said they hoped to complete it by 2019 or 2020.
A planned £80m tourist attraction on Dorset's Jurassic Coast faces an uncertain future after the sudden death of its founder, Michael Hanlon.