Boukun Tyrano-san
暴君ティラノさん · ぼうくん てぃらの さん
est. Rough estimate based on volume count, reprints and magazine — not an official figure
Overview
Ralph is the king of all dinosaurs, but when suddenly a strange big thing crashes on earth, even he is powerless against it. He awakes 65000000 years later in the modern world in Mikobayashi Kana's body, only to find that the age of the dinosaurs has ended. Now the only thing he can think of is how to return to his time, but he is not the only "modern dinosaur"...
Source: AniList
External databases: MADB · AniList
How to compare editions, collected volumes and ISBNs / Sources, updates and corrections