Thalassotitan fossil map
Where fossils of Thalassotitan have been found, shown on the Earth as it looked about 66 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 66 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 | Mosasaurs |
|---|---|
| Lived | 72.2–66 million years ago (Maastrichtian) |
| Periods | Cretaceous |
| Family | Mosasauridae |
| Named by | Longrich et al. 2022 |
| Fossil records | 3 occurrences at 3 locations (PBDB) |
| Found in | Morocco |
| Rock formations | Couche III |
About Thalassotitan
Thalassotitan ("titan of the seas") is an extinct genus of large mosasaurs (a group of extinct marine lizards) that lived during the late Maastrichtian of the Cretaceous period in what is now Morocco, around 67 to 66 million years ago. The only known species is T. atrox, described in 2022 from fossils discovered in the Ouled Abdoun Basin, initially identified as coming from other genera such as Mosasaurus or Prognathodon. Hypothetical Thalassotitan specimens may have been found in other corners of the world, although researchers also note the possibility that they come from distinct, related taxa. It is considered to be close to the genera Prognathodon and Gnathomortis, together forming the tribe Prognathodontini. The prognathodontines are separated from other mosasaurs based on their massive jaws and robust teeth.
Text in “About” is quoted from the Wikipedia article Thalassotitan (revision 1380978104), 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: Q113620659.
