Hapalodectes fossil map
Where fossils of Hapalodectes have been found, shown on the Earth as it looked about 56 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 56 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 | 61.66–37.71 million years ago (Selandian to Bartonian) |
| Periods | Paleogene |
| Family | Hapalodectidae |
| Named by | Matthew 1909 |
| Fossil records | 50 occurrences at 20 locations (PBDB) |
| Found in | United States, China, Mongolia |
| Rock formations | Willwood, Wasatch, Wind River, Naran Bulak, Chijiang, Huerfano |
About Hapalodectes
Hapalodectes (literal translation 'soft biter'; from Ancient Greek: ἁπαλός hapalos ('soft, tender') and δῆκτῆς dêktês ('biter')) is an extinct genus of otter-like mesonychians from the Late Paleocene to Early Eocene, from 62 to 44 million years ago. Although the first fossils were found in the Eocene strata of Wyoming, the genus originated in Mongolia, as the oldest species is H. dux, which was found in Late Paleocene strata in the Naran Bulak Formation. However, a more recent paper found an even older species from the Middle Paleocene.
The genus was once suggested to be related to the Archaeoceti, such as Pakicetus, due to numerous similarities between the skull and tooth anatomies of the two genera. Now, however, Hapalodectes and other mesonychians are thought to be related to basal artiodactyls, while the Archaeoceti are now determined to be descended from more derived artiodactyls, like Indohyus, which are related to hippopotamuses and anthracotheres.
H. dux possessed distinct conules on its upper molars.
Text in “About” is quoted from the Wikipedia article Hapalodectes (revision 1376757617), 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: Q901748.
