The sci-fi drama was cancelled by Fox in March, with plans for a revival on Netflix ultimately being abandoned.
Braga told Media Geek Network that the show's writing team had already outlined a "season two bible" prior to the show being dropped.
"The stuff out in the badlands, [there is] still an army out there, but we were going to find they were being massacred by what could be the possible next step in evolution for the dinosaurs," he explained.
The producer confirmed that the show's heroes would have faced the threat of "highly intelligent dinosaurs" in the planned second run.
"We do know [that creatures of that sort] existed in that time... but [they would have been] done believably," he explained.
"Then [there would be] a big showdown, and Taylor [Stephen Lang] was going to go crazy... The main source of conflict would be between Taylor and Jim Shannon [Jason O'Mara], and a battle for control of the colony and how to deal with these new dangers."
Terra Nova star Stephen Lang previously confirmed details of the planned second season to Digital Spy, revealing that the series would have gone in a "darker direction".
"They had very interesting plans for my character, I know that there was a touch of madness on the table," he confirmed. "I was looking forward to going in that direction."
> Jason O'Mara on Terra Nova: 'We were just finding our feet'
> Stephen Lang calls Terra Nova cancellation 'myopic'
Watch a clip from Terra Nova below: