Loosely based on the 1888 Jules Verne book, Two Years' Vacation.

On a school yachting trip, fifteen children of various ages are mysteriously transported to another world where dinosaurs still roam. While attempting to return home, they encounter talking dinosaurs, revolutionaries, pirates, a princess and primitive scientists. These unlikely allies help them escape from soldiers, bandits, vicious dinosaurs, and fanatical priests. Aggression between the two oldest boys leads to a split in ranks, and a sneaky double cross plot. Unlikely romances bloom in this tense atmosphere, and the group learns that each has strengths that can help them get home, if they work together.

(Source: Anime News Network)