page_title: Timeline of stegosaur research
section_title: 1980s
hierarchical_section_title: Timeline of stegosaur research / 20th century / 1980s
caption_attribution_description: English: Maiasaura panorama drawing by me user debivort october 2007.
context_page_description: This timeline of stegosaur research is a chronological listing of events in the history of paleontology focused on the stegosaurs, the iconic plate-backed, spike-tailed herbivorous eurypod dinosaurs that predominated during the Jurassic period. The first scientifically documented stegosaur remains were recovered from Early Cretaceous strata in England during the mid-19th century. However, they would not be recognized as a distinct group of dinosaurs until Othniel Charles Marsh described the new genus and species Stegosaurus armatus in 1877, which he regarded as the founding member of the Stegosauria. This new taxon originally included all armored dinosaurs. 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.
  From the time of their earliest description, the chief mystery surrounding stegosaurs was the function of their distinctive back plates. Marsh originally interpreted them as being plates of armor that would protect against predators. In 1910, Richard Swann Lull would agree with this hypothesis.
context_section_description: 1980
  Dale Russell and others reconstructed the ancient environment of Tendaguru, Tanzania as a warm coastal area that sometimes experienced droughts. The stegosaur Kentrosaurus was present there, although not especially common. Its local fossil record consists largely of "medium-sized" members of the species.
  1981
  Peter Malcolm Galton observed that stegosaurs were uncommon during the Cretaceous period.
  1982
  Dong, Tang Zilu, and Zhou Shiwu described the new genus and species Huayangosaurus taibaii as well as the Huayangosauridae.
  Nikolaï Spassov argued that the plates of stegosaurs were used as display structures in competitions over mates. Their orientation made them best suited to being viewed from the side.
  Galton studied the growth and development of Stegosaurus.
  Galton found that Kentrosaurus came in two varieties, one with an extra sacral rib. He speculated that this morph with the extra sacral rib was the female and the other morph lacking the rib was male.
  Ralph Molnar published more research on the possible Early Jurassic stegosaur track from Australia.
  Jacques Jenny and Jean-Arsène Jossen reported a possible Pliensbachian stegosaur trackway from Morocco.
  1983
  Dong, Zhou and Zhang Yihong described the new genus and species Chungkingosaurus jiangbeiensis.
  Galton and Harry Philip Powell reported stegosaur armor and vertebrae from the Early Bajocian of England. These are among the oldest known stegosaur bones.
  1984
  Giuseppe Leonardi attributed Early Cretaceous footprints of the ichnogenus Caririchnium to stegosaurs.
  Zhou observed that the Bathonian to Callovian Huayangosaurus was among the oldest known stegosaur fossils.
  Vivian de Buffrénil and others studied the histology of a Stegosaurus plate. They concluded that since the Sharpey's fibers that anchored it within the animal's skin were symmetrical it could not be moved. They also argued that there was no physical evidence in the anatomy of the plate to suggest that it was covered by horn in life. The researchers dismissed the idea that the plates could function as armor on the grounds that they were too fragile. They also doubted that the plates were used as threat displays for intimidation because "they could not unfold suddenly". They found that the plates were more likely used as sexual displays to attract mates or help regulate the animal's body temperature. They proposed that the plates were covered by a skin dense with blood vessels that helped exchange heat by both convection and radiation. They argued that their hypothesis was compatible with both major competing interpretations of dinosaur thermophysiology since if Stegosaurus was cold-blooded the plates could be used to absorb heat while if it was warm-blooded the plates could shed the excess heat that its body produced.
  David Weishampel observed that the stiff construction of the stegosaur skull rendered its jaws capable only of simple straight up-and-down movements. This distinguishes them from some other herbivorous dinosaur groups like ornithopods which were capable of complex chewing motions.
  Weishampel interpreted Stegosaurus as a browser whose diet consisted of low-growing foliage and "the fleshy parts of bennettitalean inflorescences plus the fructifications of Nilssoniales and Caytoniales plant groups."
  Xia Wei and others interpreted the ancient environment of the Lower Shaximiao Formation where Huayangosaurus was preserved as the still, shallow water of an ancient lake.
  1985
  Daniel Brinkman and Conway studied the bone texture and mineralogy of stegosaur plates.
  Galton observed that the plates of Lexovisaurus were large, thin, and rich in blood vessels like Stegosaurus plates are.
  1986
  Robert Bakker expanded on his hypothesis that stegosaurs were high browsers that fed while rearing up on their hindlimbs. He also supported the idea that stegosaur plates were mobile armor that could defend the animal's back or flanks depending on what angle to which they were flexed. He also argued that the anatomy of the tail of Stegosaurus rendered it more flexible than that of other bird-hipped dinosaurs, who
caption: Tracks supposedly left by stegosaurs in South America may actually have been left by hadrosaurs.
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