Named By: Kenneth Carpenter, Jeff Bartlett, John Bird & Reese Barrick - 2008.
Classification: Chordata, Reptilia, Dinosauria, Ornithoschia, Thyreophora, Ankylosauria, Nodosauridae, Polacanthinae.
Species: P. cedrimontanus (type).
Size: Between 5 to 5.5 meters long.
Known locations: USA, Utah - Cedar Mountain Formation, Mussentuchit Member.
Time period: Aptian/Albian of the Cretaceous.
Fossil representation: Partial skull and partial post cranial remains.
The Cedar Mountain Formation of Utah is well known for the large number of armoured dinosaur genera known to have lived in what would become Utah back in the early Cretaceous. Peloroplites however stands out from other genera however because the ulna (one of lower fore leg bones) was quite long and straight and the astralgus (ankle bone) was not fused to the shin. The hip bones of Peloroplites are also interesting in that they flare out to 55° whereas most other nodosaurids flare out to 40° or less. There has been suggestion however that this unusually wide flaring might have been produced in the fossilisation process, i.e. the bone becoming distorted with the pressures of the above sediment pressing down upon it.
Peloroplites was a quadrupedal dinosaur with short
legs. Along its
back and sides, heavy armour formed up by osteoderms (thick plates
of bone that grew in the skin, sometimes called scutes) and spikes
that would have offered a very good degree of protection from the teeth
of the predators of the time. Peloroplites is
also noted for having
robust jaws and teeth, which might in itself suggest that
Peloroplites specialised in tougher vegetation. As
a relatively short
dinosaur, Peloroplites would have been a browser
of low growing
vegetation, something which meant that it could co-exist alongside
ornithopod dinosaurs like Tenontosaurus
which could vary
their browsing range to sauropod
dinosaurs like Abydosaurus
browse upon the tree canopy.
Peloroplites would have also likely lived alongside the other armoured dinosaurs Animantarx and Cedarpelta, which are both known from the Mussentuchit Member of the Cedar Mountain Formation. Another armoured dinosaur which is known from the Yellow Cat and Ruby Ranch Members is Gastonia. Also, Sauropelta has been speculated to come from the Cedar Mountain Formation, but there has also been suggestion that these fossil remains might actually be those of Peloroplites.
- Ankylosaurs from the Price River Quarries, Cedar Mountain Formation (Lower Cretaceous), east-central Utah, Kenneth Carpenter, Jeff Bartlett, John Bird & Reese Barrick - 2008.