Sikuomys fossil map
Where fossils of Sikuomys 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 | Gypsonictopidae |
| Named by | Eberle et al. 2023 |
| Fossil records | 6 occurrences at 3 locations (PBDB) |
| Found in | United States |
| Rock formations | Prince Creek |
About Sikuomys
Sikuomys is a genus of early eutherian mammals from the Late Cretaceous of Alaska. It is known from a few teeth and part of a jawbone in deposits of Campanian age and, as of 2023, is the only known Mesozoic eutherian mammal to have lived north of the then location of the Arctic Circle. Estimated to have weighed between 6 and 18 g (0.2 and 0.6 oz), it was also unusually small for the time, similar in size to a modern shrew. It was likely insectivorous and would probably have used burrows or nests to shelter during the Arctic winter, since it is thought to have been too small to have hibernated or migrated over significant distances.
Text in “About” is quoted from the Wikipedia article Sikuomys (revision 1349836460), 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: Q124165947.
