Why are all the mosasaurs posed Like That?

[bettashark]

I almost bought the Safari Tylosaurus before realizing that it's in this pose. This very weird, very common pose. Head up, tail down, body in a vertical S, mayble kind of a spiral in some cases. Why are they all posed this way? Is this based on some science I don't know about, or maybe on a particularly famous specimen? Is it just a matter of there only being so many visually interesting ways of posing a giant monitor lizard? Maybe a matter of getting the figure to stand? Or, in Safari's case, just copying off the previous figure each time? Even PNSO does it, to some extent.
I'll be the first to admit I am in no way an expert on mosasaurs.
Here are some examples of The Pose (none of these photos are mine):

[Concavenator]

I hadn't realized this until you pointed it out. And the last one is a Dakosaurus, which isn't a mosasaurid, but a metriorhynchid.

[Fenestra]

I guess the poses capture an underwater diving motion best.
In what pose would you like to see a Mosasaurus?

[bettashark]

I hadn't realized this until you pointed it out. And the last one is a Dakosaurus, which isn't a mosasaurid, but a metriorhynchid.

Whoops, yep, you're right. Too many weird marine reptiles floating around in my head. Similar pose again though.

It just doesn't look natural to me for some reason. I was actually tempted by the latest Safari rendition because of the fine scales, but from most directions, the pose just looks... odd. Reminds me of those old depictions of weird squiggly fish-crocodile monsters from the 1800s.

[suspsy]

I fail to see what's unnatural about these poses; both mosasaurs and metriorhynchids were perfectly capable of moving their bodies that way, and they probably did during the pursuit and capture of prey. I'd much rather have marine toys posed like that instead of neutrally.

[stargatedalek]

Even living monitors would fit the descriptor of "squiggly fish crocodiles" so I agree these poses seem plenty natural. As for why they're all the same, there are just only so many semi-neutral poses a swimming animal can be in.