Reference an edge animate symbol externally

I'm trying to restart my animation with external Javascript. To do this I need to get a reference to some internal symbols. I can get a reference to the stage fine, but nothing else.

// I can get a reference to the stage

var comp = AdobeEdge.getComposition("EDGE-47431787");

  var stage = comp.getStage();

  stage.play(0);

// This is where it breaks

  stage.getSymbol("dino_animateCopy").getSymbol("dino_idle2").play(0);

  stage.getSymbol("cta_sprite_symbol_1").play(0);

  stage.getSymbol("sam_animate").play(0);

  stage.getSymbol("dino_animateCopy").getSymbol("dino_run1").play(0);

  stage.getSymbol("dino_animateCopy").play(0);

When I try to call getSymbol I get an error: TypeError: stage.getSymbol(...) is undefined. What's the correct way to reference those symbols?

Thanks