Eucastor

{{Short description|Extinct genus of rodents}}

{{Automatic taxobox

| fossil_range =

| image = Eucastor tortus (fossil beaver) (cropped).jpg

| image_caption = E. tortus, collected from Cherry County, Nebraska. At the AMNH.

| taxon = Eucastor

| authority = Leidy, 1858

}}

Eucastor is an extinct genus of beaver-grouped rodents.{{cite book |title=An Introduction to the Study of Mammals Living and Extinct

|author=William Henry Flower |author2=Richard Lydekker |publisher=A. and C. Black |year=1891 |page=[https://archive.org/details/anintroductiont00lydegoog/page/n480 458] |url=https://archive.org/details/anintroductiont00lydegoog|quote=Eucastor extinct.

}}{{cite journal |author=T. S. Palmer |title=Index Generum Mammalium |journal=North American Fauna |issue=23 |publisher=Fish and Wildlife Service |year=1904 |page=272 |url=https://books.google.com/books?id=HR5NAAAAIAAJ&q=Eucastor+extinct&pg=PA272 |doi=10.3996/nafa.23.0001|doi-access=free }}

Based on the available evidence of the foramina, Eucastor most likely is closely related to Castor, but not in its direct lineage.{{Cite journal |last=Olson |first=Everett Claire |date=1940 |title=Cranial Foramina of North American Beavers |url=https://www.jstor.org/stable/1298553 |journal=Journal of Paleontology |volume=14 |issue=5 |pages=495–501 |jstor=1298553 |issn=0022-3360}}

It has two species, the type Eucastor (formerly Castor) tortus, and E. malheurensis{{Cite web |title=Fossilworks: Eucastor |url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=41543 |access-date=2024-01-21 |website=Paleobiology Database}}

File:Eucastor tortus skull.jpg