So I'm done, just as I announced, I added grass, water and a few plants to the base...it's quite big, so the dinosaur is not firmly glued to the base (its legs are on 2 skewers so it stands straight).
Finally, I want to thank Rawen for allowing me to glue my favorite dinosaur in advance, there are definitely more skilled modelers who will manage to glue it even better than me...finally, a photo of all the dinosaurs...