Extinct Creatures-- Atopodentatus unicus (Patreon)
Content
The reason why its name focuses so much on the mouth is because the first Atopodentatus fossil was pretty squished, causing the mouth to look more like some weird forward-facing zipper of teeth, as shown above. So for a while it was portrayed as some extremely creepy-looking heckbeast, and only recently was the mistake discovered and the creature given a much more sensible mouth.
Also whoops, I realized I forgot to draw a scale comparison for this guy (which is too bad, I could have had some mermaid in there or something, it would have been good jokes), but they're about 10 feet long!