Tag: atopodentatus

Eons Roundup 11

It’s time for another batch of PBS Eons commission work!

  • An illustration of an extinct marine reptile. It has a lizard-like body and a long paddle-like tail, and a small head with an oddly-shaped wide mouth lined with many tiny teeth – the overall shape of its bizarre jaws resembles the head of a vacuum cleaner!
    Atopodentatus unicus
  • An illustration of an extinct marine reptile. It resembles a turtle with a wide squared-off beak, small spikes on the back of its head, and a wide carapace shaped vaguely like a horseshoe crab.
    Henodus chelyops

The marine reptiles Atopodentatus and Henodus, from “The Triassic Reptile With ‘Two Faces'”
https://www.youtube.com/watch?v=-8W26SiCylI

  • An illustration of an extinct giant marine turtle. it has a ridged shell like a leatherback, and a hooked eagle-like beak.
    Archelon ischyros
  • An illustration of an extinct sea turtle.
    Euclastes platyops

The marine turtles Archelon and Euclastes, from “The Return of Giant Skin-Shell Sea Turtles”
https://www.youtube.com/watch?v=Tmb8XCwb3FI

Weird Heads Month #15: Hammerhead Reptiles

Atopodentatus unicus lived in Southwest China during the early-to-mid Triassic, around 247-240 million years ago. About 3m long (9’10”), it was a marine reptile – probably part of an early branch of the sauropterygians – with an elongated streamlined body and paddle-like limbs.

When it was originally described in 2014 it seemed to have a head unlike anything seen before. The skull of the only known fossil specimen was incomplete and badly crushed, but it was reconstructed as having a downward-hooking upper jaw with a vertical split in the middle forming a zipper-like row of teeth.

An illustration of the old interpretation of Atopodentatus. It has a bizarre vertical split in the front of its snout full of needle-like teeth resembling a zipper.
The original version of Atopodentatus

But then just two years later some more complete skulls were discovered and revealed something completely different: the projections on Atopodentatus‘ snout actually stuck out to each side in a wide flat “hammerhead” shape on both its upper and lower jaws.

Not quite as bizarre as before, but still a Triassic weirdo!

It also seems to have been a rare example of a herbivorous Mesozoic marine reptile, probably rooting around on the seafloor with its shovel-like mouth, using its chisel-shaped front teeth to scoop up mouthfuls of algae and other marine plants and then straining out the water through its closely spaced needle-like back teeth.