| Mymoorapelta Temporal range: Late Jurassic,
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| Reconstructed skeleton in Wyoming Dinosaur Center | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | †Ornithischia |
| Clade: | †Thyreophora |
| Clade: | †Ankylosauria |
| Clade: | †Euankylosauria |
| Family: | †Nodosauridae |
| Genus: | †Mymoorapelta Kirkland et Carpenter, 1994 |
| Type species | |
| †Mymoorapelta maysi | |
Mymoorapelta (Meaning "Shield from the Mygatt-Moore Quarry" after a combination of the names of the discoverers of the Mygatt-Moore Quarry that fossils were originally collected from, and the Greek word πέλτα, meaning "shield") is a nodosaurid ankylosaur from the Late Jurassic (Kimmeridgian-Tithonian, around 155 to 150 million years ago) Morrison Formation (Brushy Basin Member) of western Colorado and central Utah, USA. The animal is known from a single species, Mymoorapelta maysi, and few specimens are known. The most complete specimen is the holotype individual from the Mygatt-Moore Quarry, which includes osteoderms, a partial skull, vertebrae, and other bones. It was initially described by James Kirkland and Kenneth Carpenter in 1994. Along with Gargoyleosaurus, it is one of the earliest known nodosaurids.
Mymoorapelta is one of the smaller known nodosaurids, with the estimated length of the largest specimen only reaching 3 metres (9.8 ft). It had a narrow snout and almost triangular skull in dorsal view, with two large horns pointing backwards from the brow and two horns below these that pointed backwards and down on the jugal. Five different armor types have been observed in Mymoorapelta, ranging from elongated, sharp spines on the side of the body to a giant sacral shield composed of tiny osteoderms, called ossicles, that covered the top of the pelvis. In contrast to the club-tailed ankylosaurids, the tail bore spikes that Mymoorapelta likely used for defense.
Mymoorapelta was a low browser in the Morrison ecosystem, feeding on cycads and conifers, in contrast to the high-browsing Apatosaurus known from the same quarries. Other dinosaur groups were also present, including the large theropods Allosaurus and Ceratosaurus and possibly the ornithischian Nanosaurus. Both of the theropods have also been found in association with the animal, and we have evidence that the former preyed on Mymoorapelta.