Kyouryuu Densetsu (lost build of cancelled Famicom role-playing game; 1980s)
From The Lost Media Wiki
The aforementioned screenshot from the game.
Status: Lost
Kyouryuu Densetsu (恐竜伝説 - "Dinosaur Legend") is a NES/Famicom game that was being developed by HAL Laboratory but ended up cancelled/unreleased.
It would have been an RPG set in a world populated by dinosaurs, that the hero should save, having his own dinosaur who would evolve and become more powerful (possibly in a mechanism smilar to Pokémon or EVO: Search For Eden).
There is very little information regarding this cancelled title otherwise. A small blurry screenshot is the only visual evidence left of it.