I am really irked by the sudden virality of "We've been reconstructing dinosaurs wrong, soft tissue is too unpredictable" posts like the plesiosaur one.
It's too much of a chore to have to explain osteological correlates + diapsid vs synapsid soft tissue distribution.

No, you cannot just copy-paste mammalian-style craniofacial tissues onto a diapsid. We literally know that diapsids generally have tightly-conforming craniofacial tissues that don't look too different from the basic outline of the skull, as Mark Witton pointed out.

The penguin plesiosaur thing is particularly annoying because almost no one is pointing out that penguins have extra fat on their becks BECAUSE THEY LIVE IN FREEZING TEMPERATURES. Plesiosaurs are open-ocean predators that almost probably inhabited warmer waters.

There's also the fact that long-necked plesiosaurs prob had long necks due to how schools of fish react to predators. Schools of fish will scatter the moment they see a big shadow or silhouette, so the long neck allows plesiosaurs to target fishes before the fish sees their body.