Sauropelta (/ˌsɔːroʊˈpɛltə/ SOR-oh-PEL-tə; meaning 'lizard shield') is a genus of nodosaurid dinosaur that existed in the Early Cretaceous Period of North America.

The roof of the skull was very thick and covered in flat, bony plates that are so tightly fused that there appear to be no sutures (boundaries) like the ones seen in Panoplosaurus, Pawpawsaurus, Silvisaurus, and many other ankylosaurs.

[10] Sauroplites Mymoorapelta Dongyangopelta Gastonia Gargoyleosaurus Hoplitosaurus Polacanthus Peloroplites Taohelong Sauropelta Acantholipan Nodosaurus Niobrarasaurus Ahshislepelta Tatankacephalus Silvisaurus CPC 273 (Aguja Formation specimen) Hungarosaurus Europelta Pawpawsaurus Borealopelta Stegopelta Struthiosaurus languedocensis Struthiosaurus transylvanicus Struthiosaurus austriacus Animantarx Panoplosaurus Patagopelta Texasetes Denversaurus Edmontonia longiceps Edmontonia rugosidens In the early 1930s, famed dinosaur hunter and paleontologist Barnum Brown collected the holotype specimen of Sauropelta (AMNH 3032, a partial skeleton) from the Cloverly Formation in Big Horn County, Montana.

The latter is one of the best-preserved nodosaurid skeletons known to science, includes a large amount of in situ armor, and is on display in the American Museum of Natural History in New York City.

Expeditions in the 1960s led by the equally renowned John Ostrom of Yale University's Peabody Museum of Natural History recovered additional incomplete specimens from the Cloverly.

[6] Although Ostrom originally named the species S. edwardsi, nomenclaturist George Olshevsky corrected the spelling to S. edwardsorum in 1991 to conform to Latin grammar rules.

[15] Other recent, but undescribed, discoveries include a complete skull from the Cloverly of Montana[16] and a huge fragmentary skeleton from the Cedar Mountain Formation of Utah.

In 1932, Charles Mortram Sternberg reported the presence of the footprints of a large, four-footed dinosaur from Lower Cretaceous rocks in British Columbia, Canada.

Five years later, large numbers of Tetrapodosaurus tracks were discovered at the Smoky River Coal Mine near Grande Cache, Alberta.

All specimens of S. edwardsorum were recovered from the Little Sheep Mudstone section of the Cloverly Formation in Wyoming and Montana, which has been dated to 108.5 million years ago, during the Early Cretaceous.

[19][20] Sauropelta lived in wide floodplains around rivers that drained into the shallow inland sea to the north and east, carrying sediment eroded from the low mountains to the west.

Periodic flooding of these rivers covered the surrounding plains with new muddy sediments, creating the Cloverly Formation and burying the remains of many animals, some of which would be fossilized.

At the end of Cloverly times, the shallow sea would expand to cover the entire region and would eventually split North America completely in half, forming the Western Interior Seaway.

[6][21] Microvenator, a small basal oviraptorosaur, hunted smaller prey,[6][21] while the apex predators of the Cloverly was the large carcharodontosaurid theropod Acrocanthosaurus.

[23] Lungfish, triconodont mammals, and several species of turtles lived in the Cloverly, while crocodilians prowled the rivers, lakes, and swamps, providing evidence of a year-round warm climate.

After the Cloverly ended, a large wave of Asian animals, including tyrannosaurids, ceratopsians, and ankylosaurids would disperse into western North America, forming the mixed fauna seen throughout the Late Cretaceous.