Aplodontia
The mountain beaver or sewellel is a North American rodent. It is the only living member of its genus, Aplodontia, and family, Aplodontiidae. It should not be confused with true North American and Eurasian beavers, to which it is not closely related; the mountain beaver is instead more closely related to squirrels. There are seven subspecies of mountain beaver, six of which are found in California and three of which are endemic to the state.

Western Ecological Research Center · Public Domain · via Wikipedia/Commons. May be a photograph of a specimen, or an artist’s reconstruction — an interpretation of a skeleton, since colour and soft tissue are almost never preserved.
On record
Recorded, not inferred- Also called
- mountain beaverPBDB
- Sits inside
- AplodontiidaePBDB
- Diet
- herbivorePBDB, for Aplodontiidae
- Life habit
- semifossorialPBDB
- Motility
- actively mobilePBDB, for Osteichthyes
- Environment
- terrestrialPBDB, for Eutheria
Time the record covers
At least 4.5 million years on record.
The record covers at least 4.7 Mya to 129 ka. No occurrence read is dated outside 9.4 Mya to 0 Mya.
9 occurrences of Aplodontia on record, most of them in the Pleistocene. The Paleobiology Database records this as a living group. Bar height is expected occurrences, not a count: each fossil is spread across the span it is dated to, so a tall narrow bar means tight dating and a low wide one means loose.
When
9 occurrences- Miocene10%
- Pliocene1%
- Pleistocene89%
These are dates about fossils, not the animal: the record can only begin after it arose and end before it died out, so either end may reach further. Shares are expected occurrences: a fossil dated to a span is counted partly in each period it straddles. More on what this infers.
Found in
1 formation
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The named rock units Aplodontia has been recovered from, largest first. Drawn where the rock is now, not where it formed. 8 occurrences have no formation on record, which is common for older literature.
Aplodontia and its relatives
PleistoceneWhere Aplodontia and its relatives were recorded in the Pleistocene.
Found in the same rock
203 taxa- Odocoileus6 sites
- Thomomys5 sites
- Euceratherium collinum4 sites
- Lepus4 sites
- Mephitis mephitis4 sites
- Microtus4 sites
- Neotoma4 sites
- Peromyscus4 sites
- Ursus4 sites
- Cathartes aura3 sites
- Colaptes auratus cafer3 sites
- Coragyps shastensis3 sites
- Martes americana3 sites
- Megalonyx3 sites
- Neotoma fuscipes3 sites
- Puma concolor3 sites
- Sylvilagus audubonii3 sites
- Tamiasciurus hudsonicus3 sites
- Aenocyon dirus2 sites
- Aves2 sites
- Bison2 sites
- Bubo sinclairi2 sites
- Canis latrans2 sites
- Cervus2 sites
The Paleobiology Database records 8 sites for Aplodontia, and this reads all of them. The number is how many of those sites it was catalogued from too. The 24 sharing the most are listed.
This is not a list of everything alive at the time. It is only what has come out of the same ground as this animal and been written down.
Entered from
7 references- An account of the preliminary excavations in a recently explored Quaternary cave in Shasta County, California3
- Radiocarbon dates from the mammal fauna of Crystal Caverns, El Dorado County, California1
- Phylogeny, systematics, and evolution of hypsodonty in the Aplodontiinae (Mammalia, Rodentia, Aplodontiidae), with the description of several new species1
- Oregon Caves National Monument: geologic resources inventory report1
- Moles of the Scapanus latimanus group (Talpidae, Insectivora) from the Pliocene and Pleistocene of California1
- The Pleistocene fauna of Hawver Cave1
- The exploration of Potter Creek Cave1
Each of the 9 occurrences read was entered from one of these publications, ordered by how many each accounts for. This is not a search for papers mentioning the name. Entries link to doi.org where the Paleobiology Database holds an identifier, and to its own record where it does not. Relayed as the Paleobiology Database holds them, not checked against what they resolve to.
Media and terms
Media content2
Picture of Aplodontia
- Source
- Wikipedia/Commons
- Credit
- Western Ecological Research Center
- Licence
- Public Domain
- Commercial use
- the licence allows it
CT scan
- Source
- MorphoSource
- Credit
- AMNH Mammal Collections
- Licence
- not stated by the source
- Commercial use
- cannot be read from the licence given — check the record
- Specimen
- Aplodontia rufa · AMNH:Mammals:M-142747
Smithsonian Open Access was not reached for this taxon, so this list is what the others held rather than everything there is.
The description on this site
- Licence
- CC BY-SA 4.0
This is what the site found, which is not the same as what exists.
Keep going
What may have been alongside itAplodontiidae through timeFormations of the PleistoceneThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Richardson 1829