This timeline of ankylosaur research is a chronological listing of events in the history of paleontology focused on the ankylosaurs, quadrupedal herbivorous dinosaurs who were protected by a covering bony plates and spikes and occasionally by a clubbed tail. Although formally trained scientists did not begin documenting ankylosaur fossils until the early 19th century, Native Americans had a long history of contact with these remains, which were generally interpreted through a mythological lens. The Delaware people have stories about smoking the bones of ancient monsters in a magic ritual to have wishes granted and ankylosaur fossils are among the local fossils that may have been used like this. The Native Americans of the modern southwestern United States tell stories about an armored monster named Yeitso that may have been influenced by local ankylosaur fossils. Likewise, ankylosaur remains are among the dinosaur bones found along the Red Deer River of Alberta, Canada where the Piegan people believe that the Grandfather of the Buffalo once lived.

The first scientifically documented ankylosaur remains were recovered from Early Cretaceous rocks in England and named Hylaeosaurus armatus by Gideon Mantell in 1833. However, the Ankylosauria itself would not be named until Henry Fairfield Osborn did so in 1923 nearly a hundred years later. Prior to this, the ankylosaurs had been considered members of the Stegosauria, which included all armored dinosaurs when Othniel Charles Marsh named the group in 1877. It was not until 1927 that Alfred Sherwood Romer implemented the modern use of the name Stegosauria as specifically pertaining to the plate-backed and spike-tailed dinosaurs of the Jurassic that form the ankylosaurs' nearest relatives. The next major revision to ankylosaur taxonomy would not come until Walter Coombs divided the group into the two main families paleontologists still recognize today; the nodosaurids and ankylosaurids. Since then, many new ankylosaur genera and species have been discovered from all over the world and continue to come to light. Many fossil ankylosaur trackways have also been recognized.

Prescientific

The Delaware people of what is now New Jersey or Pennsylvania had a tradition regarding a hunting party that returned with a piece of an ancient bone supposedly belonging to a monster that killed humans. One of the village's wise men instructed people to burn bits of the bone in clay spoons with tobacco and make a wish while the concoction was still smoking. This ritual could bestow such favors as success in hunting, long life, and health for one's children. This tale might be inspired by local fossils, which include ankylosaurs, Coelosaurus, Dryptosaurus, and Hadrosaurus. Traditional Navajo creation mythology portrays modern Earth as the most recent of a series of worlds. They believe that the earlier worlds were inhabited by monsters that were killed with lightning bolts wielded by the heroic Monster Slayers. The most terrifying monster of the old worlds was the Big Gray Monster, Yeitso. The Navajo of Arizona feared fossil remains, attributing them to his corpse. They believe that Yeitso's ghost still haunts his remains. Yeitso's flint-like scales may have been inspired by the fossilized armored plates of various prehistoric creatures that once lived in what is now the western US. Ankylosaurs like Ankylosaurus are one such potential candidate for the source of Yeitso's armored hide. Others include non-ankylosaurs like the Permian amphibian Eryops, Triassic phytosaurs and Desmatosuchus, as well as other armored dinosaurs like Scutellosaurus or Stegosaurus. The Piegan people of Alberta attributed the fossils of dinosaurs to the "grandfather of the buffalo" they left offerings of cloth and tobacco to this mythical creature near the Red Deer River. Ankylosaur remains are among those preserved in the area that helped inspire this legend and associated practice, as are the remains of ceratopsians, hadrosaurs, and carnivorous theropods.

19th century

1830s

1832 Quarry workers discovered a fossilized partial skeleton. The remains were sent to paleontologist Gideon Mantell, who recognized that they represented a significant scientific discovery. Mantell reported the specimen discovered by quarry workers that would later be formally named Hylaeosaurus to the Geological Society.

1833 Gideon Mantell described the new genus and species Hylaeosaurus armatus. This was the first ankylosaur ever discovered, although the group itself would not be recognized and named for many years.

1840s

1842

Early April Sir Richard Owen published his second report on British fossil reptiles, wherein he formally named the Dinosauria. Hylaeosaurus was included as a founding member and was the third dinosaur to be named.

1843 Fitzinger described the new species Hylaeosaurus mantellii.

1844 Mantell described the new species Hylaeosaurus oweni.

1850s

1856 Joseph Leidy described the new genus and species Palaeoscincus costatus. He considered it to be an herbivore.

1858 Sir Richard Owen published a study on Hylaeosaurus.

1860s

1865 Reverend William Fox discovered the Polacanthus type specimen.

1867 Sir Richard Owen described the new genus Polacanthus. He also described the new genus and species Acanthopholis horridus.

1869 Harry Govier Seeley described the new species Acanthopholis eucercus and A. macrocercus and A. platypus and A. stereocercus. He also described the new genus and species Cryptosaurus eumerus. He also described the new species Iguanodon phillipsii.

1870s

1871 Bunzel described the new genus and species Struthiosaurus austriacus. He also described the new genus and species Danubiosaurus anceps.

1875 Seeley erected the new genus Priodontognathus to house the species Iguanodon phillipsii.

1879 Seeley described the new genus and species Anoplosaurus curtonotus and Anoplosaurus major. Seeley also described the new genus and species Eucercosaurus tanyspondylus. He also described the new genus and species Syngonosaurus macrocercus.

1880s

1881 Seeley described the new genus Crataeomus, with two new species: C. lepidophorus and C. pawlowitschii. He also described the new genus and species Hoplosaurus ischyrus, the new genus and species Pleuropeltis suessi, and the new genus and species Rhadinosaurus alcinus. Hulke described the new species Hylaeosaurus foxii.

1882 The British Museum of Natural History bought a large number of fossils from Rev. Fox, including the Polacanthus type specimen.

1888 Othniel Charles Marsh described the new genus and species Priconodon crassus.

1889 Marsh described the new genus and species Nodosaurus textilis. Richard Lydekker described the new genus Cryptodraco to house the species Cryptosaurus eumerus.

1890s

1890 Marsh named the Nodosauridae. He regarded them as relatives of the stegosaurs due to the shared presence of bony plates embedded in the skin.

1892 Marsh described the new genus and species Palaeoscincus latus.

1893 Lydekker described the new genus and species Sarcolestes leedsi.

20th century

1900s

1901 F. A. Lucas described the new species Stegosaurus marshi, and later reclassified it as Polacanthus marshi.

1902 Lawrence Lambe described the new genus and species Stereocephalus tutus. He also described the new species Palaeoscincus asper. He regarded ankylosaurs as herbivores. Lucas erected the genus Hoplitosaurus to house the species "Polacanthus" marshi. Franz Nopcsa described the new genus and species Onychosaurus hungaricus.

1905 Samuel Williston described the new genus and species Stegopelta landerensis.

1908 Brown described the new genus and species Ankylosaurus magniventris. He also named the Ankylosauridae and Ankylosaurinae. He followed Marsh's 1890 suggestion that ankylosaurs and stegosaurs were close relatives.

1909 Wieland described the new genus and species Hierosaurus sternbergi.

1910s

1914 While collecting fossils in Dinosaur Provincial Park, William Edmund Cutler discovered the type specimen of an ankylosaur taxon that would later be named Scolosaurus cutleri in his honor. However, while undercutting the specimen it collapsed on him "resulting in serious upper body injuries."

1915 Nopcsa described the new species Struthiosaurus transylvanicus.

1918 Nopcsa described the new genus and species Leipsanosaurus noricus.

1919 Lambe described the new genus and species Panoplosaurus mirus.

1920s

1923 Henry Fairfield Osborn named the Ankylosauria. Charles A. Matley described the new genus and species Lametasaurus indicus.

1924 Parks described the new genus and species Dyoplosaurus acutosquameus. Hennig described the new species Polacanthus becklesi.

1927 Alfred Sherwood Romer published the first formal diagnosis for the Ankylosauria. He observed that the anatomy of the stegosaur pelvis and hindlimb as well as their primarily Jurassic age distinguished them from the mainly Cretaceous ankylosaurs. As the Stegosauria originally included all armored dinosaurs, Romer's distinction marked the beginning of the modern use of the name to refer to the plate-backed and spike-tailed dinosaurs.

1928 Nopcsa described the new genus Scolosaurus. Charles Sternberg described the new genus and species Edmontonia longiceps.

1929 Nopcsa described the new species Scolosaurus cutleri. Nopcsa described the new genus and species Polacanthoides ponderosus, and the new species Rhodanosaurus lugdunensis. Sternberg described the new genus and species Anodontosaurus lambei.

1930s

1930 Charles Whitney Gilmore described the new genus and species Palaeoscincus rugosidens.

1932 Sternberg described the new ichnogenus and species Tetrapodosaurus borealis from the Early Cretaceous Gething Formation of British Columbia, Canada. He attributed the tracks to ceratopsians, but they would later be attributed to ankylosaurs.

1933 Gilmore described the new genus and species Pinacosaurus grangeri.

1934 Chakravarti described the new genus and species Brachypodosaurus gravis.

1935 C. C. Young described the new species Pinacosaurus ninghsiensis.

1936 Mehl described the new species Nodosaurus coleii.

1940s

1940 Russell concluded that ankylosaurs chewed with a simple straight-up-and-down movement of the jaws and only fed on soft vegetation based on aspects of their skull and tooth anatomy.

1950s

1952 Evgeny Maleev described the new genus and species Syrmosaurus viminicaudus, as well as the species S. disparoserratus. Maleev described the new genus and species Talarurus plicatospineus.

1953 Birger Bohlin described the new genus and species Peishansaurus philemys. He also described the new genus and species Sauroplites scutiger, and the new genus and species Stegosaurides excavatus.

1955 Nicholas Hotton regarded ankylosaurs as herbivores.

1956 Maleev described the new species Dyoplosaurus giganteus.

1960s

1960 T. H. Eaton described the new genus and species Silvisaurus condrayi.

1963 F. H. Khakimov discovered a new dinosaur track site in Shirkent National Park, Tajikistan. Zakharov and Khakimov reported the dinosaur track site discovered by the latter to the scientific literature.

1964 Zakharov described the new ichnogenus and species Macropodosaurus gravis. He attributed it to a theropod, but these tracks are more likely to have been produced by ankylosaurs.

1969 Haas interpreted the ankylosaur diet and consisting of soft plants that ankylosaurs chewed with a simple straight-up-and-down movement of the jaws based on their skull and tooth anatomy.

1970s

1970 John Ostrom described the new genus and species Sauropelta edwardsorum.

1971