When Jurassic Park (1993) first hit theaters, audiences were absolutely stunned by the special effects. Thanks to a brilliant combination of animatronics, puppets, and top of the line CGI, moviegoers were nearly convinced the animals onscreen were living, breathing dinosaurs. If you’re interested, check out the video below to get an inside look at the ILM wizards who brought Spielberg’s creatuers to life.

Of course, a lot has changed since the first Jurassic Park was released in 1993, but audiences still love their practical effects. While Jurassic World (2015) primarily relies on computer animation, the geniuses at Legacy Effects—who’ve worked on films like Avatar (2009), Life of Pi (2012), and Avengers: Age of Ultron (2015)—were brought in to whip up a few animatronic beasties. Their most impressive achievement was creating the head and neck of the robotic Apatosaurus discovered by Chris Pratt and Bryce Dallas Howard. We could explain how much skill went into creating this critter, but really, it’s one of those things you have to see to truly appreciate.

In addition to the practical effects, Industrial Light & Magic decided to take the franchise in a totally new direction by using motion capture. Similar to how Andy Serkis played Gollum in The Lord of the Rings series and Mark Ruffalo played the Hulk, actors were brought in to play dinosaurs such as the T. rex, the Indominus rex, and most importantly, the raptor squad.

Four ILM team members were chosen to play the raptors, and each actor was equipped with a backpack, complete with a special rig to help animators capture tail movements. While the humans had a hard time maintaining those awkward Velociraptor positions, the actors played a crucial role in helping the ILM wizards animate subtle gesture and unique body language the animators might not have been able to recreate otherwise. Be sure to check out the video below for a quick glimpse into the world of motion capture monsters.