Zaisanamynodon fossil map
Where fossils of Zaisanamynodon have been found, shown on the Earth as it looked about 30 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 30 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 | 56–33.9 million years ago (Ypresian to Priabonian) |
| Periods | Paleogene |
| Family | Amynodontidae |
| Named by | Belyaeva 1971 |
| Fossil records | 20 occurrences at 7 locations (PBDB) |
| Found in | China, Japan, United States, Kazakhstan, Russia |
| Rock formations | txn:43168, Ulan Gocho, Yokawa, Clarno, Baron Sog, Houldjin |
About Zaisanamynodon
Zaisanamynodon is an extinct genus of amynodont that lived in Central Asia, East Asia, and North America during the Late Eocene. Two species of Zaisanamynodon are recognized: the type species Z. borisovi, known from the Priabonian of Kazakhstan and China, and the earlier Z. protheroi, known from the Bartonian of Russia, the United States, and perhaps Japan.
Zaisanamynodon is the largest known amynodont. Z. borisovi reached an estimated body mass of 2,720 kilograms (6,000 lb), making it comparable in size to the modern white rhinoceros. Z. protheroi was only slightly smaller, at 2,442 kilograms (5,384 lb).
Text in “About” is quoted from the Wikipedia article Zaisanamynodon (revision 1378287008), 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: Q112867373.
