With Warner Bros and Legendary kicking off the Monsterverse, you'd think they'd want as many of their legendary monsters alive and primed to kick off, which makes the fact that mega-turtle Gamera's corpse can be spotted in the opening credits a little odd.
Even more importantly though, the government and Monarch clearly have files on all of these creatures they've encountered - hence the footage under the credits. And it's not just Gamera - whose skeleton they have actual pictures of - but also Godzilla, who they tried to bomb, on camera.
This makes the fact that John Goodman's Randa has to pitch for funding to the Senate (who you'd think might have some idea of the reality of the situation - because who the hell else would, right?) utterly confusing.