Sciuromorpha

Common card · No. 434041

Sciuromorpha ( 'squirrel-like') is a rodent suborder that includes several rodent families. It includes all members of the Sciuridae (the squirrel family) as well as the mountain beaver species. 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 the rodent suborders on morphological and molecular grounds. They defined the Sciuromorpha as including three families, Sciuridae, Aplodontiidae...

Read on Wikipedia · Image Utahcamera at en.wikipedia, Public domain