Funnily enough they're toxic to all remaining dinosaurs.

> Avocado. I heard it was dinosaur food.

Nope, and this is trivial to check. Source: https://en.wikipedia.org/wiki/Avocado#Taxonomy_and_evolution

The proposed seed dispersers are now-extinct mammalian megafauna. Much more recent than the dinosaurs - 10k to 100k years ago.