Well then, I guess either you struggle with how to time it (happens), or something is done incorrectly... Kinda hard to tell without seeing a video sadly.
Your Encounter tool seems to be correct though
The important parts are :
- Start the timer and your save file at the exact same time (not a new save file, the one you saved with the ID you wrote down on the Encounter tool)
- Trigger the dialog that displays the Tortolodon right when the timer reaches zero (It's the dialog just after "And to go with it...")
Using the timer audio cue helps a lot.
If it still doesn't work, it might actually be a bug, but I doubt it as this part was tested out extensively...


