from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. A small, thick-bodied rodent (Aplodontia rufa) of the Pacific coast of North America, having tiny eyes and small ears and usually found in communal burrows dug in the banks of streams. Also called mountain beaver.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. The mountain beaver (Aplodontia rufa).

from the GNU version of the Collaborative International Dictionary of English

  • n. A peculiar gregarious burrowing rodent (Haplodon rufus), native of the coast region of the Northwestern United States. It somewhat resembles a muskrat or marmot, but has only a rudimentary tail. Its head is broad, its eyes are small and its fur is brownish above, gray beneath. It constitutes the family Haplodontidæ. Called also boomer, showt'l, and mountain beaver.

from The Century Dictionary and Cyclopedia

  • n. A rodent mammal of the family Haplodontidæ, Haplodon rufus, inhabiting Washington and Oregon and parts of California

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. bulky nocturnal burrowing rodent of uplands of the Pacific coast of North America; the most primitive living rodent


Chinook šwalál, robe of sewellel skins.
(American Heritage® Dictionary of the English Language, Fourth Edition)
From Chinook sewellel, shewellel ("mountain beaver pelt robe"). (Wiktionary)


  • This extinct mammal, related to the living sewellel, is the only known horned rodent and the smallest horned mammal.

    Science Press Releases

  • The name "sewellel" was applied to the robes which they made from the skins; the animal is called "show'tl," by some Indian tribes. —

    Original journals of the Lewis and Clark Expedition, 1804-1806

  • The southern part of British Columbia contains the mule deer of western North America (_Mazama macrotis_), and a very strange rodent, the sewellel or mountain beaver (_Haplodon_), a creature distantly allied to squirrels, marmots, and beavers, but restricted in its distribution to a few parts of California, Oregon, and British

    Pioneers in Canada

  • 1 The sewellel (Haplodon rufus) belongs to a family which seems to be intermediate between those of the squirrel and the beaver.

    Original journals of the Lewis and Clark Expedition, 1804-1806


Log in or sign up to get involved in the conversation. It's quick and easy.