Land of the Lost (1991)

The Porter family, Tom, Kevin, and Annie get sucked into a prehistoric alternative world while taking a family vacation. The Porters build a tree house, hook up with a few locals, Tasha- orphaned, extra smart dinosaur, Stink-monkey man, and Christa-another human who has lived in the Land of the Lost since she was a little girl. The Porters must deal with living with dinosaurs and avoiding the evil advanced Sleestaks. Theere mom was long dead before they got there and there aren't any "early humanoids" there either.