From NintendoWiki, your source on Nintendo information. By fans, for fans.
Dinosaur Planet is the basis of and former name of the game which became Star Fox Adventures for Nintendo GameCube. It was in development for Nintendo 64.
Originally, Star Fox Adventures did not feature Star Fox characters, but rather had original protagonists instead. Krystal was one of the two original protagonists, who has since been adopted into the Star Fox series. The other original protagonist was a wolf named Sabre. The two were half siblings, with Sabre's father, Randorn, having adopted Krystal.
The game was converted into Star Fox Adventures halfway through development, following Shigeru Miyamoto's suggestion to bring Dinosaur Planet into the Star Fox universe. Shigeru Miyamoto has stated that the characters Fox and Sabre are visually similar.
In the final game, Dinosaur Planet (renamed Sauria in Star Fox Assault) is the main setting of the story.