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.
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
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.
Like other nodosaurs, 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 and Eolambia which could vary their browsing range to sauropod dinosaurs like Abydosaurus which could 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.