US Geological Survey
Date of this Version
3-2008
Citation
Order Soricomorpha Gregory, 1910. pp. 177-187, (March 2008).
Abstract
Neal Woodman and Jaime Péfaur
The Soricomorpha originally was proposed by Gregory (1910) as a "section" containing the shrews (Soric:idae) and moles (Talpidae) within the suborder Lypotyphla, order Insectivora. More recent concepts of what constitutes the Soricomorpha vary. Typically, the order comprises shrews and solenodons (Solenodontidael, and possibly tenrees (Tenrecidae; McKenna and Bell 1997) or moles (Amason et al. 2002) or both (MacPhee and Novacek 1993). A possible relationship with gymnures and hedgehogs (Erinacidae) also has received support (Malia, Adkins, and Allard 2002). Previously, these five families had been included with golden moles (Chrysochloridae) in the order Lypotyphla, or along with elephant shrews (Macroscelididae) in the order Insectivora. However, recent analyses of phylogenetic relationships indicate that the seven families are not as closely related as previously believed (e.g., Stanhope et a!. 1998; Mouchaty et al. 2000; Amason et al. 2002; Malia, Adkins, and Allard 2002). Although consensus has yet to be reached on their relative phyletic positions, either to each other or to other mammalian groups, recent classifications (e.g., McKenna and Bell 1997) divide the Erinacidae, Soricidae. Solenodonridae, T alpidae, and Tenrecidae among many as four orders (Macroscelidea, Cbrysochloridea, Erinaceomorpha, and Soricomorpha). Only one of these families, the Soricidae, is present in South America.
Family Soricidae G. Fischer, 1814
The Soricidae comprises 23 genera and more than 320 species distributed throughout Eurasia, Africa, North and Central America, and northwestern South America. Members of the family are sometimes considered primitive or generalized, but these labels ignore a well-known suite of cranial and dental specializations unique to these animals. Shrews are small mammals (head and body length, 35-150 mm; mass, 2-106 g), typically having small pinnae often concealed by fur, minute eyes, and an elongated, pointed snout. The long, flattened skull has incomplete zygomatic arches lacking jugals, free tympanic bones (auditory bullae are lacking), and a double articulation of the articular condyle of the dentary with the cranium. The clavicle is long and slender, and the pubic symphysis is open (innominates not in contact). The deciduous dentition is shed in utero. A pincer-like foraging apparatus is formed by the large, curved, first upper incisor and the long, procumbent, first lower incisor. Behind the first upper incisor, the anterior upper dentition (incisors, canine, and anterior premolars) is comparatively simple and undifferentiated, and these teeth are often referred to as "unicuspids." Homologies of the unicuspids have been difficult to determine, and for this reason, dental formulae for individual species often disagree in the relative numbers of incisors, canines. and premolars. Only shrews of the subfamily Soricinae occur in the Americas. The red-pigmented dentition in most New World genera (except Megasorex and Notiosorex) provides an additional characteristic that aids in distinguishing these mammals as shrews.
Although most authors attribute the name Soricidae to Gray (1821:300), Palmer (1904) and McKenna and Bell (1997) dated the name from G. Fischer's ([= Fischer von Waldheim] 1817:414) "Familia Soricinorum." However, G. Fiscber first used "Familia Soricinorum" in 1814 (p. xl.