Temporal range: Late Triassic
|An artist's illustration of Henodus chelyops|
At four feet long, it may be one of the shortest placodonts, but it was certainly the widest. It was 54 inches wide, and weighed 100 pounds.
Henodus chelyops also had a single tooth on each side of its mouth, though the remaining teeth were replaced by a beak. Instead, it had baleen-like denticles along the jaws, which combined with a unique feature of the hyoid and musculature indicative of rapid jaw closing indicate a filter feeding lifestyle. The head was squared-off at the front, just ahead of the eyes.
More recently, however, it has been suggested that this placodont was likely an aquatic herbivore, scraping off vegetation from the bottom with its broad jaws. This suggestion has been brought up in a paper discussing the habits and morphology of Atopodentatus, another Mesozoic aquatic reptile formerly suggested to be a filter-feeder and bearing strongly convergent jaw adaptations, including a similar "hammerhead" jaw tips, though unlike Atopodentatus it's still believed that Henodus relied on filter feeding to obtain plant-matter from the substrates.
In Popular Culture
- Henodus makes a brief appearance in Sea Monsters: A Prehistoric Adventure, where it is seen during the timeline scene. It also appears in the video game based off of this documentary, where it is a playable creature.
- Henodus can be created in the Aquatic Park of Jurassic Park: Builder as a limited edition creature.
- Henodus appears in the underwater section for the game Jurassic World: The Game as a VIP reef creature in the solid gold pack