Mymoorapelta

Mymoorapelta was a compact, heavily armoured herbivore that inhabited North America during the Late Jurassic period. Discovered in the rich bonebeds of the Morrison Formation in western Colorado, it was roughly three metres long and shared its floodplain ecosystem with giant sauropods and theropods. Its body was covered in a mosaic of protective dermal armour, including broad triangular plates over the hips and sharp spines along the flanks. Because it lived before the classic divide between tail-clubbed ankylosaurids and spike-shouldered nodosaurids was fully established, its exact classification remains debated. It fed on low-lying cycads and ferns, using its low stature and protective carapace to withstand attacks from predators like Allosaurus.

It was the first pre-Cretaceous ankylosaur known from well-preserved skeletal material in North America.

Where and when

Mymoorapelta lived in the Late Jurassic, from 155 to 148 million years ago (Kimmeridgian-Tithonian age). Its remains come from United States, in the Morrison Formation.

The numbers

Length 3 m (estimates run from 2.7 to 3.2 m). Mass about 390 kg. Hip height about 0.9 m. That is 1.8 human-lengths, or 0.27 of a double-decker bus. These are estimates from partial skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Mymoorapelta with a bus Place on the timeline