Hyotheridium fossil map
Where fossils of Hyotheridium have been found, shown on the Earth as it looked about 75 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 75 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 | Early mammals |
|---|---|
| Lived | 83.6–72.2 million years ago (Campanian) |
| Periods | Cretaceous |
| Family | Palaeoryctidae |
| Named by | Gregory and Simpson 1926 |
| Fossil records | 2 occurrences at 1 locations (PBDB) |
| Found in | Mongolia |
| Rock formations | Djadokhta |
About Hyotheridium
Hyotheridium is a possible Eutherian from the Late Cretaceous (?late Santonian–early Campanian) Djadochta Formation of Mongolia. It also could be a Deltatheriid, although the fossil, a poorly preserved skull with the upper and lower jaws connected in a way that makes them hard to separate and to examine, makes it difficult to determine what it is.
Text in “About” is quoted from the Wikipedia article Hyotheridium (revision 1381432961), 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: Q5957139.
