Hylaeosaurus fossil map
Where fossils of Hylaeosaurus have been found, shown on the Earth as it looked about 130 million years ago and on today’s map.
Dots are fossil collections recorded in the Paleobiology Database. The “then” view moves today’s fossil sites back to their positions 130 million years ago (the time slice nearest the median age of the fossils) using the Merdith et al. (2021) plate model; positions are approximate. Open on the timeline map →
| Group | Stegosaurs & ankylosaurs |
|---|---|
| Lived | 139.1–110.1 million years ago (Berriasian to Albian) |
| Periods | Cretaceous |
| Family | Nodosauridae |
| Named by | Mantell 1833 |
| Fossil records | 10 occurrences at 9 locations (PBDB) |
| Found in | United Kingdom, Germany, France |
| Rock formations | txn:38817, Tunbridge Wells Sand, Bückeberg, Weald Clay, Ashdown, Wadhurst Clay |
About Hylaeosaurus
Hylaeosaurus ( hy-LEE-o-SOR-əs) is a herbivorous ankylosaurian dinosaur that lived about 136 million years ago, in the late Valanginian stage of the early Cretaceous period of England. It was found in the Grinstead Clay.
Hylaeosaurus was one of the first dinosaurs to be discovered, in 1832 by Gideon Mantell. In 1842 it was one of the three dinosaurs Richard Owen based the Dinosauria on, the others being Iguanodon and Megalosaurus. Four species were named in the genus, but only the type species Hylaeosaurus armatus is today considered valid. Only limited remains have been found of Hylaeosaurus and much of its anatomy is unknown. It might have been a basal nodosaurid, although a recent cladistic analysis recovers it as a basal ankylosaurid.
Hylaeosaurus was about five metres long. It was an armoured dinosaur that carried at least three long spines on its shoulder.
Text in “About” is quoted from the Wikipedia article Hylaeosaurus (revision 1368881463), licensed under CC BY-SA 4.0; introduction excerpted verbatim, formatting removed. Ages, family, authority and fossil records: Paleobiology Database, accessed 23 October 2026. Ages are those of the rock layers the fossils were found in. Wikidata: Q131770.
