Synonyms that are in the dictionary are marked in green. Synonyms that are not in the dictionary are marked in red.
Antonyms that are in the dictionary are marked in green. Antonyms that are not in the dictionary are marked in red.
So the idea is a bit older; the idea really was about 10 years ago--maybe more, actually, now.
Source: https://screenrant.com/prehistoric-planet-season-2-producers-interview/