Information:  - The mountain beaver ("Aplodontia rufa") is a North American rodent. It has several common names, including: aplodontia, mountain boomer, ground bear, and giant mole. The name sewellel beaver comes from "sewellel" or "suwellel", the Chinookan term for a cloak made from its pelts. This species 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.  - Rodents (from Latin "rodere", "to gnaw") are mammals of the order Rodentia, which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents; they are found in vast numbers on all continents except Antarctica. They are the most diversified mammalian order and live in a variety of terrestrial habitats, including human-made environments.  - Mammals are any vertebrates within the class Mammalia (from Latin "mamma" "breast"), a clade of endothermic amniotes distinguished from reptiles and birds by the possession of a neocortex (a region of the brain), hair, three middle ear bones and mammary glands. The sister group of mammals may be the extinct "Haldanodon." The mammals represent the only living Synapsida, which together with the Sauropsida form the Amniota clade. The mammals consist of the Yinotheria including monotrema and the Theriiformes including the theria.  - The term Sciuromorpha has referred to numerous groups of rodents , but the only family common to all variations is the Sciuridae , the squirrels . Most definitions also include the mountain beaver . Traditionally , the term has been defined on the basis of the shape of the infraorbital canal . A sciuromorphous zygomasseteric system is characterized by attachment of the lateral masseter muscle along the side of the rostrum . Unlike hystricomorphous and myomorphous rodents , the medial masseter muscle does not pass through the infraorbital canal . Among extant rodents , only the families Sciuridae , Castoridae , Heteromyidae , and Geomyidae are truly sciuromorphous . Some authorities would exclude the Geomyidae and Heteromyidae from that list due to the attachment of the medial masseter directly behind the zygomatic arch. Carleton and Musser ( 2005 ) redefined rodent suborders on the basis of a host of both morphological and molecular reasons . They defined the Sciuromorpha as including three families , Sciuridae , Aplodontiidae , and Gliridae . Of these , only the Sciuridae are truly sciuromorphous . The Aplodontiidae are protrogomorphous and the Gliridae are myomorphous . The connection between Aplodontiidae and Sciuridae has been proposed numerous times in the past . The two families have been united into a common infraorder ( Sciurida ) or superfamily ( Sciuroidea ) . It has long been suggested that dormice ( Gliridae ) are not particularly related to the Myomorpha , and their zygomasseteric structure has been termed `` pseudomyomorphy '' . The connection between squirrels and dormice has been almost exclusively suggested through genetic studies , and to a lesser degree via the fossil rodent Reithroparamys .  - The Eurasian beaver or European beaver ("Castor fiber") is a species of beaver which was once widespread in Eurasia. It was hunted to near-extinction for both its fur and castoreum; and by 1900, only 1200 beavers survived in eight relict populations in Europe and Asia. Reintroduced through much of its former range, it now occurs from Great Britain to China and Mongolia, although it is absent from Italy, Portugal, the southern Balkans, and the Middle East.  - A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant, or other type of organism. The term typically refers to the zone in which the organism lives and where it can find food, shelter, protection and mates for reproduction. It is the natural environment in which an organism lives, or the physical environment that surrounds a species population.    What is the relationship between 'sciuromorpha' and 'rodentia'?
The answer to this question is:
parent taxon