Insectivora

(vertebrate zoology) An order of mammals including hedgehogs, shrews, moles, and other forms, most of which have spines.

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An order of placental mammals including shrews, moles, and hedgehogs. The tree shrews (Tupaiidae) and elephant shrews (Macroscelididae) are now recognized as unrelated, and they are placed in separate orders (Scandentia and Macroscelidea). Formerly thought to be the basal placental order, from which other orders were derived, the Insectivora is now restricted to members of the former suborder Lipotyphla. It evolved side by side with the other placental orders, with a fossil record going back to the Paleocene. A number of fossil families from the Cretaceous and early Tertiary, formerly included in the Insectivora, are classified as Proteutheria.

Living lipotyphlous insectivores are small animals: the largest (Potamogale) weighs about 1 kg (2 lb). Most eat insects, worms, and other invertebrates, for which they search in ground litter and vegetation, using their highly developed olfactory sense and their mobile, sensitive snouts. Some burrow, such as moles; some are aquatic, such as the desman. Anatomically, they are distinguished by the absense of a cecum on the intestine, reduction of the pubic symphysis, and characters of the skull. The cheek teeth typically have sharp cusps and crests, and the incisors are often enlarged to act as forceps. Insectivores are found on all continents except Australia and Antarctica, but only one genus (Cryptotis, a shrew) has reached South America.

Three suborders can be distinguished: Erinaceomorpha, Soricomorpha, and Chrysochloromorpha. Living erinaceomorphs belong to the family Erinaceidae, comprising the spiny hedgehogs (Erinaceinae) of Eurasia and Africa and the hairy moonrats (Echinosoricinae) of Southeast Asia.

Four living families are included in the Soricomorpha: Soricidae (shrews), Talpidae (moles, desman), Tenrecidae (Madagascan tenrecs and African otter shrews), and Solenodontidae (Solenodon, confined to Cuba and Hispaniola). True moles did not reach North America until the Miocene; they were preceded in the Oligocene by the Proscalopidae. The living Solenodon, in the West Indies, is one of the largest insectivores, but nevertheless shrewlike. The Tenrecidae are far removed geographically from other soricomorphs. They probably evolved in Africa, where their fossil history goes back to the early Miocene, and the otter shrews (Potamogalinae) survive on the continent of Africa today. The remainder are in Madagascar where, like the lemurs, they have evolved in diverse directions during a long time of isolation. In some ways, for example brain size, they have remained more primitive than other insectivores.

The golden moles (Chrysochloridae) are put into a separate suborder, Chrysochloromorpha. They are highly specialized burrowers, using large claws on the forefoot. They are confined to Africa, where fossils show that they were already specialized in the early Miocene. See also Mammalia; Mole (zoology); Shrew; Solenodon.

n.

    "See," cries the chorus of admiring preachers,
    "How Providence provides for all His creatures!"
    "His care," the gnat said, "even the insects follows:
    For us He has provided wrens and swallows."
                                                         Sempen Railey

The order of mammals containing insectivorous animals such as senrecs, moles, shrews and hedgehogs.

European Hedgehog (Erinaceus europaeus)

The extinct Macrocranion tupaiodon

The order Insectivora (from Latin insectum "insect" and vorare "to eat") is a now-abandoned biological grouping within the class of mammals. Some species have now been moved out leaving the remaining ones in order Eulipotyphla, within the larger clade Laurasiatheria, which makes up one of the most basic clades of placental mammals.

Contents 1 History 2 Taxonomy 3 Classification 4 References

History

In the past, the grouping was used as a scrapbasket for a variety of small to very small, relatively unspecialised, insectivorous mammals. Since any primitive-looking fossil groups of placental mammals were commonly assigned to this order for convenience, it was held to constitute the basal stock out of which other placental orders had evolved. Therefore, at its widest extent, the order Insectivora represented an evolutionary grade rather than a clade.

Taxonomy

The taxonomy has been refined in recent years, and treeshrews, elephant shrews, and colugos have now been placed in separate orders, as have many fossil groups that were formerly included here. For some time it was held that the remaining insectivoran families constituted a monophyletic grouping, or clade, to which the name Lipotyphla had long been applied. However, molecular evidence indicated that Chrysochloridae (golden moles) and Tenrecidae (tenrecs) also should be separated as a new order Afrosoricida.

Erinaceidae (hedgehogs) was then also split off into a separate order (Erinaceomorpha) from the remainder (termed Soricomorpha), comprising the families Soricidae (shrews), Talpidae (moles), Solenodontidae and Nesophontidae.^[1] These two orders then replaced Insectivora. This scheme was undermined when molecular studies indicated that Soricomorpha is paraphyletic, because Soricidae shared a more recent common ancestor with Erinaceidae than with other soricomorphs.^[2]

However, the combination of Soricidae and Erinaceidae, referred to as order Eulipotyphla, has been shown to be monophyletic.^[3]

Classification

• ORDER EULIPOTYPHLA (= 'Insectivora')
  • Family Erinaceidae
    • Subfamily Erinaceinae: hedgehogs
    • Subfamily Hylomyinae: moonrats and gymnures
  • Family Soricidae
    • Subfamily Crocidurinae: white-toothed shrews
    • Subfamily Soricinae: red-toothed shrews
    • Subfamily Myosoricinae: African white-toothed shrews
  • Family Talpidae
    • Subfamily Desmaninae: desmans
    • Subfamily Talpinae: moles
    • Subfamily Uropsilinae: shrew moles
  • Family Solenodontidae: solenodons
  • Family Nesophontidae: extinct West Indian shrews

Family-level cladogram of extant insectivoran relationships, following Roca et al.:^[2]

Eulipotyphla	Solenodontidae Talpidae Soricidae Erinaceidae

These families have been placed within Insectivora in the past:

• Family Chrysochloridae (golden moles)
• Family Tenrecidae (tenrecs)
• Family Macroscelididae (elephant shrews)
• Family Tupaiidae (treeshrews)
• Family Cynocephalidae (colugos)

Not to be confused with insectivores (the eaters of insects considered as a feeding behavior), many of which do not belong to Eulipotyphla or the other taxa formerly included within Insectivora.

References

1. ^ Hutterer, Rainer (16 November 2005). Wilson, Don E., and Reeder, DeeAnn M.. ed. Mammal Species of the World (3rd ed.). Baltimore: Johns Hopkins University Press, 2 vols. (2142 pp.). pp. 212–311. ISBN 978-0-8018-8221-0. OCLC 62265494. http://www.bucknell.edu/msw3. 
2. ^ ^{a b} Roca, A.L., G.K. Bar-Gal, E. Eizirik, K.M. Helgen, R. Maria, M.S. Springer, S.J. O'Brien, and W.J. Murphy (2004). "Mesozoic origin for West Indian insectivores". Nature 429 (6992): 649–651. doi:10.1038/nature02597. PMID 15190349. 
3. ^ Robin MD Beck, Olaf RP Bininda-Emonds, Marcel Cardillo, Fu-Guo Robert Liu and Andy Purvis (2006). "A higher level MRP supertree of placental mammals". BMC Evolutionary Biology 6: 93. doi:10.1186/1471-2148-6-93. PMC 1654192. PMID 17101039. http://www.biomedcentral.com/1471-2148/6/93. 

v d e Extant mammal orders by infraclass Kingdom Animalia Phylum Chordata Subphylum Vertebrata (unranked) Amniota Australosphenida Monotremata (Platypus and echidnas) Metatheria (Marsupial inclusive) Ameridelphia Paucituberculata (Shrew opossums) Didelphimorphia (Opossums) Australidelphia Microbiotheria (Monito del Monte) Notoryctemorphia (Marsupial moles) Dasyuromorphia (Quolls and dunnarts) Peramelemorphia (Bilbies and bandicoots) Diprotodontia (Kangaroos and relatives) Eutheria (Placental inclusive) Xenarthra Cingulata (Armadillos) Pilosa (Anteaters and sloths) Afrotheria Afrosoricida (Tenrecs and golden moles) Macroscelidea (Elephant shrews) Tubulidentata (Aardvark) Hyracoidea (Hyraxes) Proboscidea (Elephants) Sirenia (Dugongs and manatees) Laurasiatheria Soricomorpha (Shrews and moles) Erinaceomorpha (Hedgehogs and relatives) Chiroptera (Bats) Pholidota (Pangolins) Carnivora Perissodactyla (Odd-toed ungulates) Artiodactyla (Even-toed ungulates) Cetacea (Whales and dolphins) Euarchontoglires Rodentia (Rodents) Lagomorpha (Rabbits and relatives) Scandentia (Treeshrews) Dermoptera (Colugos) Primates

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