Despite being only 22 minutes in length, the special took three years to develop and create.
The video game that Bonnie and Mason play is the fictional video game "Buzz Lightyear: Attack on Zurg" from Toy Story 2 (1999). When Reptillus Maximus turns off the console, Buzz Lightyear can be seen flying. Also, earlier in the short, as Bonnie throws the backpack the sound effects are the same as the video game.
The title is a reference to 1924 novel by Edgar Rice Burroughs and 1975 movie based on said novel, La terra dimenticata dal tempo (1974), a fantasy adventure set during WWI about a group of people who end up stranded on a huge uncharted tropical land mass where dinosaurs still live.
The promo poster, that was unveiled at Comic-con for this short, was created by Mike Mignola, a famous comic book artist and creator of Hellboy (2004), a popular superhero comic book character.