Visible crew/equipment: When Baby tries to walk, and he falls over, as he falls you can see the black sleeve covering the puppeteer's arm.
Dinosaurs (1991)
1 visible crew/equipment mistake in season 2 - chronological order
Starring: Jessica Walter, Stuart Pankin, Leif Tilden, Jason Willinger
Other mistake: A time card reads 6,000,002 BC, when it should've read "60,000,002 BC". (00:07:12)
Baby: I'm a big boy.