font settings

Font Size: Large | Normal | Small
Font Face: Verdana | Geneva | Georgia

Sciuromorpha

(Suborder)

Overview

[ Back to top ]

The term Sciuromorpha has referred to numerous groups of . In fact, 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. Theydefined the Sciuromorpha as including three families, Sciuridae, Aplodontiidae, and Gliridae. Of these, only Sciuridae is truly sciuromorphous. Aplodontiidae is protrogomorphous and Gliridae is myomorphous. The connection between Aplodontiidae and Sciuridae has been proposed on 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.

Current Families

[ Back to top ]

The suborder Sciuromorpha contains 307 living species in 61 genera and three families.

Historical Families

[ Back to top ]

Photos

[ Back to top ]

Taxonomy

[ Back to top ]

The Suborder Sciuromorpha is a member of the Order Rodentia. Here is the complete "parentage" of Sciuromorpha:

The Suborder Sciuromorpha is further organized into finer groupings including:

Families

[ Back to top ]

Allomyidae

[more]

Aplodontidae

The Mountain Beaver (Aplodontia rufa) is a primitive unrelated to beavers and not always found in mountainous areas. It has several common names including Aplodontia, 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. [more]

Castoridae

The family Castoridae contains the two living species of and their fossil relatives. This was once a highly diverse group of rodents, but is now restricted to a single genus, Castor.
[more]

Eutypomyidae

[more]

Ischyromyidae

[more]

Mylagaulidae

[more]

Reithroparamyidae

[more]

Rhizospalacidae

[more]

Sciuridae

The Sciurids or are a large family of rodents. The word Sciuridae means "shade-tail," and refers to the bushy appendage possessed by many of its members. It includes tree squirrels, ground squirrels, chipmunks, the marmots (which include woodchucks), and the true flying squirrels. The African scaly-tailed flying squirrels, which belong to the family Anomaluridae, are not sciurids. Sciurids are found in all continents except Australia and Antarctica. [more]

Theridomyidae

[more]

At least 18 species and subspecies belong to the Family Theridomyidae.

More info about the Family Theridomyidae may be found here.

References

[ Back to top ]

Sources

[ Back to top ]
Last Revised: November 19, 2008