I feel like a lot of people on here, are reaching deep into their big bag of guesswork, and speculating that every MOTW for this series is linked to some prehistoric version of the animal that it's based on.
Solely, because the main baddies are based on dinos.
If that were the case, Toei/Tv-Asahi would've put up the same info for the baddies on how they are based on dino + weapon, on the page for the MOTW. They don't. All they have is the name of the modern animal they have a likeness to.