Lizards. BIG lizards.

Hello world,
A new species of moniter lizard has been found in the Philipines. It's been named the Sierra Madre Forest Lizard, and has been decided to be a keystone species. They, much like bees, spread the seeds of trees by eating their fruit. The discoverers do not think it is venomous, since it is vegetarian (except for the occasional snail). Not many people have known about this lizard until now, except for the local tribes. These people use the lizards as their main source of protein. Hopefully its not under the threat of extinction. I wonder why they haven't been discovered till now.
Here's the link;
http://news.discovery.com/animals/giant-monitor-lizard.html