Sir David Attenborough answers dinosaur query from Otis, 4

It was the ultimate curveball bedtime question: "Mummy, will we be extinct one day like the dinosaurs?"

Four-year-old Otis had his mum Gerry "stumped" - so the pair came up with a plan to write to nature's oracle, Sir David Attenborough.

And, to their amazement, the 94-year-old sent a handwritten response.

"The answer is that we need not do so as long as we look after our planet properly", Sir David wrote reassuringly.

Gerry, 38, a communications officer for medical research at Cardiff University, said she thought "honesty was the best policy", after Otis had asked the existential question.

"I said I didn't know the answer - but I hoped not. So I told him about climate change and how we need to look after our planet," she explained.

"We also talked about the work lots of amazing people, like Sir David and Greta Thunberg, are doing to make sure people are taking action to make a difference," she said.

"When I explained about global warming, his little eyes were on stalks, but I tried to focus on the small things we could do to help like recycling our rubbish, driving the car less and eating less meat."

They sent their question to Sir David the following morning, with a little card and a dinosaur drawing Otis had made.

And both were "staggered" to receive a reply about three days later.

"There's something really special and poignant about a 94-year-old conservationist, who has spent his life working to save the planet, corresponding with a four-and-a-half-year-old who's just at the very beginning of his journey to understand the impact of climate change and our behaviour on the planet," said Gerry.

"I'm a science communicator myself and I think it's so important that kids learn from a very young age about what's happening and the action we need to take."

As for Otis, he was thrilled to receive the reply, which has increased his interest in nature even more.

"He's really fascinated by Venus flytraps at the moment so he's been watching video clips of Sir David talking about them," said Gerry.

"His little face just lit up when I read the letter to him this morning. He knows who Sir David is and that he's special - but I think he'll need to be a bit older before he really understands the significance.

"Sir David is just a wonderful human being. He's worked so tirelessly to help us all understand our own impact on the planet and how important it is for us to take action now.

"He has that innate ability to inspire and engage people, whether it's speaking at UN climate change talks or writing to a young boy about the dinosaurs. He's a national treasure who has inspired generations."