Following in the noble footsteps of Roy Scheider and Blake Lively, it’s finally time for Jason Statham to do battle with a large shark. Judging by the fact that those three actors have never been mentioned in the same breath before, shark movies have taken a downturn in quality since “Jaws.” A dorsal fin sneaking through the water is now the sign of SyFy Channel schlock— or worse, “Jaws 4: The Revenge.” But what if a shark movie knew that it was as frivolous as “Jaws 4: The Revenge”? Enter “The Meg.”

Meg is short for Megalodon: a gargantuan, prehistoric shark that has surfaced in modern times to feed on movie stars. The narrative follows a team of research scientists as they dive beneath the Mariana Trench, unveiling a deeper part of the ocean that’s swimming with new species—and ancient ones, including the 75-foot monster shark.

Even in an intentionally dumb movie, this doesn’t make much sense: if Megalodon sharks have been evolving in complete darkness for millions of years, why doesn’t the sun obliterate the Meg’s eyes? Why doesn’t the lack of pressure near the surface affect it? One might think that the war between Jason Statham and a Megalodon need not maintain an adequate level of intelligence, but that expectation is muddled when “The Meg” tries to be smart from time to time.

The movie’s tone isn’t silly enough to achieve the guilty B-movie pleasure of, say, “Sharknado”. From the self-importance of its scientific jargon to the emphasis on a hackneyed “man vs. nature” theme, “The Meg” too often forgets to be as ridiculous as it could be. This is a movie in which a fish the size of a WWII submarine attacks beachgoers in floaties, for shark’s sake. But other set pieces insufficiently utilize the movie’s biggest attraction: a shark that’s, you know, big. You could swap the Megalodon for an unusually sized Great White and much of “The Meg” would remain unchanged. When your shark is 75 feet long, you can get a little more creative than rehashing scenes from every other shark horror movie.

Good thing “The Meg” is a comedy too. Rainn Wilson is there to crack wise and poke fun at the genre, and Jason Statham’s jump on the joke train is as satisfying as his turn in “Spy”. There’s even a non-grating child actress who pulls off that sweet spot of adorable and funny. When “The Meg” acknowledges how unrealistic its sense of scale is, it’s worth a lot of laughs. The movie is never funnier than the first scene, though — it treats a Megalodon attack like high drama, winking heavily with fast zooms and overly somber dialogue. The dissonance of taking a ludicrous situation with dead seriousness is undeniably comical.

But “The Meg” loses that sense after the opening scene, and fails to go far enough in the other direction of embracing absolute absurdity. It exists somewhere in the middle of that spectrum — fun in the moment, but not outlandish enough to sink its teeth into your brain. Perhaps you’d be better off with next month’s “The Last Sharknado,” which adds superheroes and dinosaurs to the sharks-in-a-tornado mix. Now that’s a summer movie.

★★★   (3/5)