Andrewsarchus fossil map
Where fossils of Andrewsarchus have been found, shown on the Earth as it looked about 45 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 45 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 | 48.07–37.71 million years ago (Lutetian to Bartonian) |
| Periods | Paleogene |
| Named by | Osborn 1924 |
| Fossil records | 2 occurrences at 2 locations (PBDB) |
| Found in | China |
| Rock formations | Irdin Manha, Dongjun |
About Andrewsarchus
Andrewsarchus, meaning "Andrews' ruler", is an extinct genus of artiodactyl that lived during the Middle Eocene in what is now China. The genus was first described by Henry Fairfield Osborn in 1924 with the type species A. mongoliensis based on a largely complete cranium. A second species, A. crassum, was described in 1977 based on teeth. A mandible, formerly described as Paratriisodon, probably belongs to the Andrewsarchus as well. The genus has been historically placed in the families Mesonychidae or Arctocyonidae, or was considered to be a close relative of whales. It is now regarded as the sole member of its own family, Andrewsarchidae, and may have been related to entelodonts. Fossils of Andrewsarchus have been recovered from the Middle Eocene Irdin Manha, Lushi and Dongjun Formations of Inner Mongolia, each dated to the Irdinmanhan Asian land mammal age (Lutetian stage, 47.8–42.7 million years ago).
Text in “About” is quoted from the Wikipedia article Andrewsarchus (revision 1380944419), licensed under CC BY-SA 4.0; introduction excerpted verbatim, formatting removed. Ages, family, authority and fossil records: Paleobiology Database, accessed 22 October 2026. Ages are those of the rock layers the fossils were found in. Wikidata: Q133214.
