Pantosaurus fossil map
Where fossils of Pantosaurus have been found, shown on the Earth as it looked about 160 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 160 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 | Plesiosaurs & kin |
|---|---|
| Lived | 161.5–154.8 million years ago (Oxfordian) |
| Periods | Jurassic |
| Family | Cryptoclididae |
| Named by | Marsh 1893 |
| Fossil records | 6 occurrences at 5 locations (PBDB) |
| Found in | United States |
| Rock formations | Sundance |
About Pantosaurus
Pantosaurus ("all lizard") is an extinct genus of plesiosaur from the Late Jurassic (Oxfordian) of what is now Wyoming. It lived in what used to be the Sundance Sea. It was originally named Parasaurus ("near lizard") by Othniel Charles Marsh in reference to Plesiosaurus, but that name was preoccupied, and Marsh changed it. The species Muraenosaurus reedii is in fact a junior synonym of Pantosaurus. The holotype YPM 543 is a partial articulated skeleton, partially prepared to yield a distal humerus, four articulated carpals, a fragment of the coracoid, and several isolated cervical vertebrae from the Upper Member of the Sundance Formation. Other material includes USNM 536963, USNM 536965, UW 3, UW 5544 and UW 15938.
Text in “About” is quoted from the Wikipedia article Pantosaurus (revision 1292674449), 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: Q7131914.