It looks like a bit of wood, but it tells a much bigger story of immigration and inspiration. A story as big as a dinosaur.

This is where Jurassic Park began. It's when we actually stared walking with dinosaurs. In fact it's the moment humans first realised dinosaurs existed, and, like the rest of us, it immigrated to New Zealand and has found its home here.

Amongst the collections at Te Papa - and a dead-cert for our list - is a simple fossilised tooth that is truly a world first and the envy of dinosaur fanatics worldwide. It's a tooth that was discovered near Brighton, in England, around 1820 by Mary Ann Mantell and her husband, Gideon. The couple were passionate fossil collectors and one day Mary Ann - or was it Gideon? Both stories have been told - found some large teeth on the side of the road. Experts struggled to identify them. Rhinoceros? Crocodile? Some kind of large lizard?

How were they to know it belonged to an Iguanodon, a creature that weighed around three tonnes and could be 13 metres long? As 16 year-old dinosaur enthusiast and our guide for this episode, Eric London says, for those trying to make sense of the fossil record two hundred years ago, "it's kind of like a real life dragon".

"Of course you can imagine in the 1800s," says Dr Hamish Campbell, Te Papa’s geologist in residence from GNS Science, "how did educated people get their head around the concept of extinction? It really didn’t exist until the discovery of dinosaurs and then bingo, people started realizing wow, there must have been organisms around on this planet that ware no longer here so it kick-started the whole investigation of dinosaurs as well as raising the concept of extinction.”

And it began with this tooth, the very first fossil to be recognized as dinosaur.

"This is like the Holy Grail," says Campbell.

"it kind of led us to realize what these creatures were, where they’d come fro and well, it basically started off our knowledge about dinosaurs in general so stuff like Jurassic Park," London adds. "All the cool things that stem from dinosaurs kind of started with that tooth…. You know, it’s pretty cool.”

Even though it looks like a bit of wood. So how did it end up in New Zealand?…

Go to this episode on rnz.co.nz for more details