Let's just get this right out of the way. Atopodentatus had one messed-up mug. Its upper jaw was split in the middle and lined with small teeth on each side of the gap. If Atopodentatus were a body louse, Cthulhu would be its host.
But Atopodentatus didn't have much of a taste for blood. It's teeth are too small and fragile to actively take down prey like fish and it probably couldn't exert much force with its jaws. The reptile may have tilted its head to trawl the bottom of shallow coastal areas and, like a sieve, trapped small invertebrates behind its toothy gap. It was a 10-foot-long filter feeder similar to a baleen whale. All teeth and no bite.
The fossil hails from Luoping, China, where a massive haul of specimens has shown that this bizarre marine reptile from 245 million years ago was in good company. Ichthyosaurs, long-necked Dinocephalosaurus, sea urchins and isopods have been unearthed in the same area. Atopodentatus unicus can take comfort at least in being the weirdo king of this Triassic menagerie.