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''Lavanify'' is a mammalian genus from the late Cretaceous (probably Maastrichtian, about 71 to 66 million years ago) of Madagascar. The only species, ''L. miolaka'', is known from two isolated teeth, one of which is damaged. The teeth were collected in 1995–1996 and described in 1997. The animal is classified as a member of Gondwanatheria, an enigmatic extinct group with unclear phylogenetic relationships, and within Gondwanatheria as a member of the family Sudamericidae. ''Lavanify'' is most closely related to the Indian ''Bharattherium''; the South American ''Sudamerica'' and ''Gondwanatherium'' are more distantly related. Gondwanatheres probably ate hard plant material. ''Lavanify'' had high-crowned, curved teeth. One of the two teeth is 11.2 mm high and shows a deep furrow and, is centered laterally in the crown, a V-shaped area that consists of dentine. The other, damaged, tooth is 9.8 mm high and has at least one deep cavity (infundibulum). Characters shared by the teeth of ''Lavanify'' and ''Bharattherium'' include the presence of an infundibulum and a furrow; they both also have large, continuous bands of matrix (unbundled hydroxyapatite crystals) between the prisms (bundles of hydroxyapatite crystals) of the enamel, and perikymata—wave-like ridges and grooves in the enamel surface. ==Discovery and context== Two teeth of ''Lavanify'' were discovered in 1995–1996 during joint expeditions of the State University of New York, Stony Brook University, and the University of Antananarivo to the late Cretaceous (mostly Maastrichtian, about 71 to 66 million years ago ()) Maevarano Formation of northwestern Madagascar.〔Krause et al., 1997, p. 504; 2006, p. 179〕 The two teeth were found in different sites in a white sandstone unit of the Maevarano Formation near the village of Berivotra and have been deposited in the collections of the University of Antananarivo (specimen UA 8653) and Field Museum of Natural History (specimen FMNH PM 59520). David Krause and colleagues described ''Lavanify'' and a sudamericid from India, which they did not name, in a 1997 paper in ''Nature''. These were the first gondwanathere mammals to be found outside of Argentina and provided evidence that the mammal faunas of the different Gondwanan (southern) continents were similar to each other. The generic name, ''Lavanify'', means "long tooth" and the specific name, ''miolaka'', means "curved" in Malagasy; both refer to the teeth's shape.〔Krause et al., 1997, p. 504〕 Gondwanatheres are a small group of mammals of uncertain phylogenetic affinities known from the late Cretaceous to the Eocene (~56–34 mya) of the Gondwanan continents, known only from teeth and a few lower jaws. Upon their discovery in the 1980s, gondwanatheres were initially thought to be xenarthrans—part of the same group as living sloths, armadillos, and anteaters—but later workers have favored affinities with multituberculates (a diverse group of fossil mammals) or left the relationships of the gondwanatheres open. The group comprises two families. The family Ferugliotheriidae, whose members had low-crowned teeth, occurs in the Campanian (~84–71 mya) to Maastrichtian of Argentina. All other gondwanatheres, including ''Lavanify'', are placed in the Sudamericidae, which have high-crowned (hypsodont) teeth. These include ''Gondwanatherium'' from the Campanian and Maastrichtian of Argentina; ''Sudamerica'' from the Paleocene (~66–56 mya) of Argentina; ''Lavanify''; at least one species from the Maastrichtian of India; an unnamed species related to ''Sudamerica'' from the Eocene of Antarctica; and an unnamed possible gondwanathere, TNM 02067, from the Cretaceous of Tanzania.〔Wilson et al., 2007, p. 521〕 In 2007, teams led by G.P. Wilson and G.V.R. Prasad independently described this animal as ''Dakshina'' and ''Bharattherium'' respectively; as the latter name was published first, it is the correct name for this genus according to the Principle of Priority.〔Prasad, 2008, p. 91〕 Gondwanatheres have been interpreted as feeding on roots, bark, and abrasive vegetation or as the earliest grass-eating mammals.〔Gurovich and Beck, 2009, p. 37; Wilson et al., 2007, p. 521〕 Several other mammals have been recorded from the late Cretaceous of Madagascar, mostly on the basis of isolated teeth. A possible second gondwanathere is represented by a tooth that is larger and lower-crowned than those of ''Lavanify'', and a yet lower-crowned tooth may also be of a gondwanathere. A lower molar, UA 8699, may be of a marsupial or a placental and a molar fragment is referable to Multituberculata. Finally, an as-yet-undescribed mammal is known from a fairly complete skeleton. None of these mammals is related to the living mammals of the island, many of which belong to unique groups (see List of mammals of Madagascar).〔Krause et al., 2006, pp. 186–188〕 The fauna also contains crocodyliforms, dinosaurs, and other animals.〔Krause et al., 2006, p. 178〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Lavanify」の詳細全文を読む スポンサード リンク
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