Jurassic Park stars Sam Neill and Laura Dern stunned by 20-year age gap

Laura Dern and Sam Neill have reprised their characters in the Jurassic World: Dominion. Photo / Getty Images

When they filmed Jurassic Park back in 1992, Sam Neill and Laura Dern had no idea they shared a rather significant age gap.

The Hollywood heavyweights played love interests Dr Alan Grant and Dr Ellie Sattler in the Steven Spielberg dinosaur classic.

But it wasn't until Neill, now 74, read an article titled, Old Geezers and Gals, that he realised he was "20 years older than Laura".

He told The Sunday Times there were "people like Harrison Ford and Sean Connery acting with much younger people, and there I was on the list. I thought, 'Come on. It can't be true.'"

He added: "At the time [it] was a completely appropriate age difference for a leading man and lady!"

Sam Neill and Laura Dern in Jurassic Park. Photo / Supplied

Neill would've been 45 when the first Jurassic Park was filmed, while Dern was 26.

But Dern, now 55, said it felt "completely appropriate to fall in love with Sam Neill".

"It was only now, when we returned in a moment of cultural awareness about the patriarchy, that I was like, 'Wow! We're not the same age?'" Dern added.

The duo, along with fellow original star Jeff Goldblum, have reprised their characters in the upcoming Jurassic World: Dominion, the third and final film in the blockbuster Jurassic World franchise.

Chris Pratt and Bryce Dallas Howard return as leads Owen Grady and Claire Dearing, respectively, while director Colin Trevorrow is back at the helm.

Laura Dern, foreground, and Sam Neill, right in a scene from Jurassic World Dominion. Photo / AP

The World franchise is a monster, with the debut film in 2016 making $1.6 billion at the global box office.

Speaking to news.com.au in November, Neill said the cast had a "great reunion", which marked their first time back in the Jurassic-sphere since Jurassic Park III in 2001.

"We all enjoy each other's company. When I think of the new cast, Chris Pratt and Bryce Dallas Howard, we just all had a lovely time," he said.

"It's massive. We had 120 different sets and several hundred dinosaurs. It's a big production."

• Jurassic World: Dominion hits NZ cinemas on June 9.