Performed during my 2:06:28.

Carrying fire through the waterfall at the end of Millipedes and sneaking it past the waterfall at the beginning of Brontosaurus brings Brontosaurus from being one of the longest stages in the game to one of the shortest.

Note that this isn't possible with a post-game save, as selecting Brontosaurus from the menu at that point will start you off with a preset weapon and amount of ammo. In the context of a full game run, you can start the stage with a lit spear in hand.

I use a fast spear drop setup based on a visual cue, pick it up fast, use diagonal movement to run more quickly past the brontos, and light the bushes in three separate spots so that they burn quickly. This strategy skips the entire quest of running down the canyon and back to find fire and fighting a ton of dinos along the way, saving around 5 minutes.

In this particular run I bonked into Carl and lost some time, so hopefully I'll improve on this one soon.