A unicuspid is a tooth that has only one

cusp A cusp is the most pointed end of a curve. It often refers to cusp (anatomy), a pointed structure on a tooth. Cusp or CUSP may also refer to: Mathematics * Cusp (singularity), a singular point of a curve * Cusp catastrophe, a branch of bifu ...

In shrews

The dental formulas of

shrew Shrews ( family Soricidae) are small mole-like mammals classified in the order Eulipotyphla. True shrews are not to be confused with treeshrews, otter shrews, elephant shrews, West Indies shrews, or marsupial shrews, which belong to dif ...

s are distinguished by the number of unicuspids. All shrews have (in one half of each jaw) one large

incisor Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, wher ...

followed by a variable number of unicuspids, followed by a complex

premolar The premolars, also called premolar Tooth (human), teeth, or bicuspids, are transitional teeth located between the Canine tooth, canine and Molar (tooth), molar teeth. In humans, there are two premolars per dental terminology#Quadrant, quadrant in ...

, followed by three

molars The molars or molar teeth are large, flat tooth, teeth at the back of the mouth. They are more developed in mammal, mammals. They are used primarily to comminution, grind food during mastication, chewing. The name ''molar'' derives from Latin, '' ...

. All shrews except for those of the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Myosorex ''Myosorex'' is a mammal genus in the Soricidae (shrew) family. The genus, collectively referred to as the mouse shrews, contains these species: * Babault's mouse shrew, ''M. babaulti'' * Montane mouse shrew, ''M. blarina'' * Bururi forest shr ...

'' have one lower unicuspid; ''Myosorex'' has two. The

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

'' Blarina'', '' Blarinella'', and ''

Sorex The genus ''Sorex'' includes many of the common shrews of Eurasia and North America, and contains at least 142 known species and subspecies. Members of this genus, known as long-tailed shrews, are the only members of the tribe Soricini of the s ...

'' have five upper unicuspids. The genera ''Myosorex'', '' Feroculus'', '' Scutisorex'', '' Suncus'', ''

Sylvisorex The forest shrews are the members of the genus ''Sylvisorex''. They are mammals in the family Soricidae and are found only in Africa. The genus name comes from the Latin world "silva" which means "forest" and "sorex", which means "shrew-mouse". ...

'', '' Ruwenzorisorex'', '' Cryptotis'', '' Neomys'', '' Soriculus'', and '' Episoriculus'' have four upper unicuspids. The genera '' Congosorex'', '' Surdisorex'', '' Solisorex'', '' Paracrocidura'', ''

Crocidura The genus ''Crocidura'' is one of nine genera of the shrew subfamily Crocidurinae. Members of the genus are commonly called white-toothed shrews or musk shrews, although both also apply to all of the species in the subfamily. With over 180 sp ...

'', ''

Chimarrogale The Asiatic water shrews are the members of the genus ''Chimarrogale''. They are mammals in the subfamily Soricinae of the family Soricidae. They are aquatic, with some species inhabiting streams. The genus contains the following species: * Mala ...

'', ''

Chodsigoa ''Chodsigoa'' is a genus of shrews in the tribe Nectogalini. Species There are currently ten species classified under the genus ''Chodsigoa'': *Van Sung's shrew (''Chodsigoa caovansunga'') (Lunde, Musser and Son, 2003) *''?Chodsigoa hoffmanni ...

'', '' Megasorex'', '' Nectogale'', and '' Notiosorex'' have three upper unicuspids. The genera '' Diplomesodon'' and '' Anourosorex'' have two upper unicuspids.Merritt, Joseph F. ''Advances in the Biology of Shrews II''. New York: International Society of Shrew Biologists. 2005.

References

Teeth {{Dentistry-stub