This whole scene is so sweet, they’re practically speaking the same language even though Judai’s not familiar with fossils.
It is a nice moment and it is a problem that these scenes between them are just flashbacks. Jim’s determination to save Judai would have meant a lot more if we had actually seen these moments earlier in the season. Granted, they didn’t really have much time to do something like that, especially when they were emphasizing a connection between Judai and Johan more than anyone else out of the new cast, but this would have been more effective and less sudden if their friendship had been established a lot sooner.