The mountain beaver (Aplodontia rufa) is a rodent unrelated to beavers and that is not usually found in mountainous areas. It has several common names including aplodontia and sewellel. This species is the only member of its genus, Aplodontia, and family, Aplodontiidae. Scientific classification - Wikipedia /**/ @import /skins/monobook/IE50Fixes. ... Phyla Subkingdom Parazoa Porifera (sponges) Subkingdom Agnotozoa Placozoa Orthonectida Rhombozoa Subkingdom Metazoa Radiata Cnidaria Ctenophora - Comb jellies Bilateria Protostomia Acoelomorpha Platyhelminthes - Flatworms Nemertina - Ribbon worms Gastrotricha Gnathostomulida - Jawed worms Micrognathozoa Rotifera - Rotifers Acanthocephala Priapulida Kinorhyncha Loricifera Entoprocta Nematoda - Roundworms Nematomorpha - Horsehair worms Cycliophora Mollusca - Mollusks Sipuncula - Peanut worms Annelida - Segmented... Typical Classes Subphylum Urochordata - Tunicates Ascidiacea Thaliacea Larvacea Subphylum Cephalochordata - Lancelets Subphylum Myxini - Hagfishes Subphylum Vertebrata - Vertebrates Petromyzontida - Lampreys Placodermi (extinct) Chondrichthyes - Cartilaginous fishes Acanthodii (extinct) Actinopterygii - Ray-finned fishes Actinistia - Coelacanths Dipnoi - Lungfishes Amphibia - Amphibians Reptilia - Reptiles Aves - Birds Mammalia - Mammals Chordates (phylum Chordata) include the vertebrates, together with... Orders Subclass Monotremata Monotremata Subclass Marsupialia Didelphimorphia Paucituberculata Microbiotheria Dasyuromorphia Peramelemorphia Notoryctemorphia Diprotodontia Subclass Placentalia Xenarthra Dermoptera Desmostylia Scandentia Primates Rodentia Lagomorpha Insectivora Chiroptera Pholidota Carnivora Perissodactyla Artiodactyla Cetacea Afrosoricida Macroscelidea Tubulidentata Hyracoidea Proboscidea Sirenia The mammals are the class of vertebrate animals primarily characterized by the presence of mammary... Families Many, see text The order Rodentia is the most numerous of all the branches on the mammal family tree. ... In biology, binomial nomenclature is a standard convention used for naming species. ... 1829 was a common year starting on Thursday (see link for calendar). ... Families Many, see text The order Rodentia is the most numerous of all the branches on the mammal family tree. ... Species C. canadensis C. fiber Beavers are semi-aquatic rodents native to North America and Europe. ...

Habits and Distribution

Mountain beavers are found in coastal areas of the Pacific Northwest of North America. These are usually low elevation regions, but they can occasionally be seen as high as treeline. These animals appear to be physiologically limited to moist regions with minimal snowfall and cool winters. They do not appear to be able to conserve body heat or warmth as efficiently as other rodents. Darker red states are always part of the Pacific Northwest. ... World map showing location of North America A satellite composite image of North America North America is the third largest continent in area and in population after Eurasia and Africa. ... In this view of an alpine tree-line, the distant line looks particularly sharp. ...

Mountain beavers build elaborate burrow systems with chambers devoted to fecal and food caches. They exhibit caprophagy and will remove fecal pellets directly using their incisors. Food includes fleshy herbs and young shoots of more woody plants. They appear to be strictly vegetarian. Feces (also spelled faeces in British English, or fæces) are semi-solid waste products from the digestive tract expelled through the anus (or cloaca) during defecation. ... For animals adapted to eat primarily plants, sometimes referred to as vegetarian animals, see Herbivore. ...

These chunky animals weigh about 800+ grams and are 300-460 mm long with a tail length equal to 10-40 mm.

The breeding season is between January-March with 2-3 young born February-April. Longevity is 5-10 years, fairly long as rodents go. Longevity is long life or existence. ...

Spelling the Family Name

Most references use the spelling Aplodontidae for the family name. This has been deemed incorrect due to the technical rules of convertinga genus name into a family name. The proper conversion of Aplodontia to a family name is to drop the -a only and add -idae. Thus, Aplodontiidae is technically correct. This spelling is gaining acceptance in modern texts.

Closest Relatives

The mountain beaver is considered a living fossil by many researchers due to the presence of a host of primitive characters, particularly the protrogomorphous zygomasseteric system. The mountain beaver is the only living rodent with this primitive cranial and muscular feature (except perhaps the mole rats who clearly evolved protrogomorphy from a hystricomorphous ancestor). The mountain beaver was once thought to be related to the earliest protrogomorphous rodents such as the ischyromyids like Paramys. Both molecular and morphological phylogeneticists have recently suggested a more distant relationship to these animals. Living fossil is a term for any living species which closely resembles a species otherwise only known from fossils, i. ... Molecular phylogeny is the use of a genes molecular characteristics to classify an organism and to place it on a map of evolutionary relationships known as the phylogenetic tree. ... Phylogenetics (Greek: phylon = race and genetic = birth) is the taxonomical classification of organisms based on how closely they are related in terms of evolutionary differences. ...

Molecular results have consistently produced a sister relationship between the mountain beaver and the squirrels (family Sciuridae). This clade is referred to as Sciuroidea, Sciuromorpha (not to be confused with the sciuromorphous zygomasseteric system), or Sciurida depending on the author. Genera Several, see text Squirrel is the common name for rodents of the family Sciuridae. ... Genera Many: see text. ... Greek clados = branch) or phylogenetic systematics is a branch of biology that determines the evolutionary relationships of living things based on derived similarities. ...

According to the fossil record, The Aplodontoidea split from the squirrels in the Middle or Late Eocene as indicated by the extinct genera Spurimus and Prosciurus. The fossil record for the genus Aplodontia itself extends to the Late Pleistocene of North America. FOSSIL is a standard for allowing serial communication for telecommunications programs under DOS. FOSSIL stands for Fido Opus SEAdog Standard Interface Layer and was made by a group of Fidonet sysops to make their software work on different machines. ... The Eocene epoch (55-37 mya) is a major division of the geologic timescale and the second epoch of the Tertiary period in the Cenozoic era. ... The Pleistocene epoch is part of the geologic timescale, usually dated as 1. ...

Mountain beavers have an unusual projection on each molar and premolar which is unique among mammals and allows for easy identification of teeth. A molar is the fourth kind of tooth in mammals. ... The premolar teeth or bicuspids are transitional teeth located between the canine and molar teeth. ...

References

• Adkins, R. M. E. L. Gelke, D. Rowe, and R. L. Honeycutt. 2001. Molecular phylogeny and divergence time estimates for major rodent groups: Evidence from multiple genes. Molecular Biology and Evolution, 18:777-791.

• MacDonald, D. ed. 1987. The Encyclopedia of Mammals. Facts on File Publications, New York.

• McKenna, Malcolm C., and Bell, Susan K. 1997. Classification of Mammals Above the Species Level. Columbia University Press, New York, 631 pp. ISBN 0-231-11013-8

• Nowak, R. M. 1999. Walker's Mammals of the World, Vol. 2. Johns Hopkins University Press, London.