Tricleidus fossil map
Where fossils of Tricleidus 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 | 184.2–154.8 million years ago (Toarcian to Oxfordian) |
| Periods | Jurassic |
| Family | Cryptoclididae |
| Named by | Andrews 1909 |
| Fossil records | 3 occurrences at 3 locations (PBDB) |
| Found in | United Kingdom, Norway |
| Rock formations | Oxford Clay, txn:38174 |
About Tricleidus
Tricleidus is an extinct genus of cryptoclidid plesiosaur known from only specimen (BMNH R3539) from the middle Jurassic of United Kingdom. It was first named by Andrews in 1909 and the type species is Tricleidus seeleyi.
One species, T. svalbardensis, was moved into Colymbosaurus in 2012. It was found in the Agardhfjellet Formation, Norway.
Text in “About” is quoted from the Wikipedia article Tricleidus (revision 1368543680), 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: Q3079606.
