View source for Lavanify

{{short description|Mammalian genus from the late Cretaceous}}
{{Use dmy dates|date=July 2018}}
{{Use shortened footnotes|date=May 2025}}
{{speciesbox
| fossil_range = [[Late Cretaceous]] (?[[Maastrichtian]])
| genus        = Lavanify
| parent_authority    = [[David W. Krause|Krause]] et al., 1997
| species      = miolaka
| authority    = [[David W. Krause|Krause]] et al., 1997
}}

'''''Lavanify''''' is a mammalian genus from the [[late Cretaceous]] (probably [[Maastrichtian]], about 71 to 66 million years ago) of [[Madagascar]]. The only species, '''''L.&nbsp;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 [[phylogeny|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-[[crown (tooth)|crowned]], curved teeth. One of the two teeth is 11.2&nbsp;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&nbsp;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 [[tooth enamel|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 [mya]) [[Maevarano Formation]] of northwestern Madagascar.<ref>Krause et al., 1997, p.&nbsp;504; 2006, p.&nbsp;179</ref> 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&nbsp;8653) and [[Field Museum of Natural History]] (specimen FMNH PM 59520). [[David W. Krause]] and colleagues described ''Lavanify'' and a [[sudamericidae|sudamericid]] from India, which they did not name, in a 1997 paper in ''[[Nature (journal)|Nature]]''. These were the first [[gondwanathere]] mammals to be found outside of Argentina and provided evidence that the mammal faunas of the different [[Gondwana]]n (southern) continents were similar to each other. The [[name of a biological genus|generic name]], ''Lavanify'', means "long tooth" and the [[specific name (zoology)|specific name]], ''miolaka'', means "curved" in [[Malagasy language|Malagasy]]; both refer to the teeth's shape.<ref name=Kea504>Krause et al., 1997, p.&nbsp;504</ref>

Gondwanatheres are a small group of mammals of uncertain [[phylogeny|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 [[xenarthra]]ns—part of the same group as living [[sloth]]s, [[armadillo]]s, and [[anteater]]s—but later workers have favored affinities with [[multituberculate]]s (a diverse group of fossil mammals) or left the relationships of the gondwanatheres open. The group comprises two [[family (biology)|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.<ref>Wilson et al., 2007, p.&nbsp;521</ref> 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]].<ref>Prasad, 2008, p.&nbsp;91</ref> Gondwanatheres have been interpreted as feeding on roots, bark, and abrasive vegetation or as the earliest [[grass-eating]] mammals.<ref>Gurovich and Beck, 2009, p.&nbsp;37; Wilson et al., 2007, p.&nbsp;521</ref>

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 (tooth)|molar]], [[UA&nbsp;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]]).<ref>Krause et al., 2006, pp.&nbsp;186–188</ref> The fauna also contains [[crocodyliform]]s, [[dinosaur]]s, and other animals.<ref>Krause et al., 2006, p.&nbsp;178</ref>

==Description==
''Lavanify'' is known from the complete cheektooth UA&nbsp;8653 and the broken tooth FMNH PM 59520. Krause and colleagues could not determine whether the teeth were from the lower or upper jaw and whether they were molars or molariform (molar-like) [[premolar]]s, but suggested that they represented two different tooth positions.<ref name=Kea504/> However, Wilson and colleagues in 2007 tentatively identified UA&nbsp;8653 as a left fourth (last) lower molariform (mf4); because molars and premolars of gondwanatheres cannot be reliably distinguished, the term "molariform" is used instead.<ref>Wilson et al., 2007, pp.&nbsp;522, 526</ref> FMNH PM 59520 resembles the ''Gondwanatherium'' fossil MACN Pv-RN 1027,<ref>Gurovich, 2005, p. 383</ref> a broken tooth that may be an upper molariform.<ref>Gurovich, 2005, p. 359</ref> In both ''Lavanify'' teeth, the enamel surface features [[perikymata]] (ridges and grooves arranged in a transverse, wave-like pattern).<ref name=Wea526/>

UA&nbsp;8653, the [[holotype]], is hypsodont and curved. It is 11.2&nbsp;mm high, of which the crown makes up about 85%, and the dimensions of its crown are 3.4 x 3.2&nbsp;mm. The [[Occlusion (dentistry)|occlusal]] (chewing) surface is worn flat and contains a V-shaped island of [[dentine]] surrounded by [[tooth enamel|enamel]]. One side of the crown lacks enamel.<ref name=Kea504/> Between the two arms of the V, at the lingual (inner) side of the tooth,<ref name=Wea526>Wilson et al., 2007, p.&nbsp;526</ref> is a furrow filled with [[cementum]], which extends all the way through the tooth; the presence of such a long furrow distinguishes it from ''Gondwanatherium''. The enamel is made up of small, round prisms (bundles of [[hydroxyapatite]] crystals) that are separated by large, continuous bands of [[interprismatic matrix]] (IPM; the material between the enamel prisms).<ref name=Kea504/>

FMNH PM 59520 is 9.8&nbsp;mm high. It is similar in many respects to UA&nbsp;8653, but is less curved and its occlusal surface contains a large [[wikt:infundibulum|infundibulum]] (funnel-shaped cavity), filled with cementum and surrounded by enamel that penetrates deeply into the tooth. There is also either a second infundibulum or a cementum-filled furrow. The differences in degree of curvature and occlusal morphology suggest that this tooth represents a different tooth position than UA&nbsp;8653. Krause and colleagues tentatively placed this tooth in ''Lavanify'' in view of the considerable variation among other gondwanathere teeth of a single species and in the absence of evidence to the contrary.<ref name=Kea505>Krause et al., 1997, p.&nbsp;505</ref>

==Relationships==
{{cladogram|align=right
|caption=Relationships among gondwanatheres<ref>Krause et al., 1997, fig.&nbsp;3; Wilson et al., 2007, p.&nbsp;527; Prasad et al., 2007, p.&nbsp;23</ref>
|clades=
{{clade|1=
{{clade
|1=[[Ferugliotheriidae]]
|label2=[[Sudamericidae]]
|2={{clade
   |1=''[[Gondwanatherium]]''
   |2={{clade
      |1=''[[Sudamerica]]''
      |2={{clade
         |1='''''Lavanify'''''
         |2=''[[Bharattherium]]''
         }}
      }}
    }}
}}
}}
}}
In their original description, Krause and colleagues suggested that ''Lavanify'' was most closely related to the then-unnamed Indian sudamericid. They based this proposed relationship on the shared presence of prominent, continuous bands of IPM.<ref name=Keaf3>Krause et al., 1997, fig.&nbsp;3</ref> The teams who named the Indian gondwanathere in 2007 both agreed with this proposed relationship.<ref>Prasad et al., 2007, p.&nbsp;23; Wilson et al., 2007, p.&nbsp;526</ref> In their description of ''Dakshina'', Wilson and colleagues added the presence of an infundibulum and of perikymata to the evidence for the relationship between the two. These three characters are [[synapomorphy|synapomorphies]] (shared derived traits) for the ''Bharattherium-Lavanify'' [[clade]]. They also share the presence of furrows on the lingual side of the teeth only, but whether this is a derived feature is uncertain. Wilson and colleagues list two [[autapomorphy|autapomorphies]] (unique derived traits) of ''Lavanify'': presence of a V-shaped dentine island and absence of enamel on one side of the crown.<ref name=Wea526/> Prasad and colleagues who named ''Bharattherium'', noted the absence of enamel on part of the crown of a ''Bharattherium'' tooth and interpreted this trait as a synapomorphy of ''Bharattherium'' and ''Lavanify''.<ref name=Pea21>Prasad et al., 2007, p.&nbsp;21</ref> They also mentioned the presence of a furrow and infundibulum as shared traits.<ref>Prasad et al., 2007, pp.&nbsp;21–22</ref>
{{Clear}}

==References==
{{Portal|Paleontology|Mammals}}
{{Reflist|colwidth=30em}}

==Literature cited==
*Gurovich, Y. 2005. {{usurped|1=[https://web.archive.org/web/20110717194315/http://vertebratepaleo.com/downloads/GondwanatheriaThesis.pdf Bio-evolutionary aspects of Mesozoic mammals: description, phylogenetic relationships and evolution of the Gondwanatheria (Late Cretaceous and Paleocene of Gondwana)]}}. Ph.D. thesis, Universidad de Buenos Aires, xiii + 546 pp.
*Gurovich, Y. and Beck, R. 2009. [https://dx.doi.org/10.1007/s10914-008-9097-3 The phylogenetic affinities of the enigmatic mammalian clade Gondwanatheria] (subscription required). Journal of Mammalian Evolution 16:25–49.
*Krause, D.W., Prasad, G.V.R., von Koenigswald, W., Sahni, A. and Grine, F.E. 1997. [http://www.nature.com/nature/journal/v390/n6659/pdf/390504a0.pdf Cosmopolitanism among gondwanan Late Cretaceous mammals] (subscription required). Nature 390:504–507.
*Krause, D.W., O'Connor, P.M., Rogers, K.C., Sampson, S.D., Buckley, G.A. and Rogers, R.R. 2006. [https://www.jstor.org/stable/40035721 Late Cretaceous terrestrial vertebrates from Madagascar: Implications for Latin American biogeography] (subscription required). Annals of the Missouri Botanical Garden 93(2):178–208.
*Prasad, G.V.R. 2008. {{cite web |url=http://www.iypeinsa.org/updates-09/art-18.pdf |title=Sedimentary basins & fossil records |url-status=dead |archive-url=https://web.archive.org/web/20110726200353/http://www.iypeinsa.org/updates-09/art-18.pdf |archive-date=26 July 2011 }} Pp.&nbsp;90–96 in Singhvi, A.K. and Bhattacharya, A. (eds.). Glimpses of Geoscience Research in India: The Indian Report to IUGS 2004–2008. New Delhi: The Indian National Science Academy (INSA).
*Prasad, G.V.R., Verma, O., Sahni, A., Krause, D.W., Khosla, A. and Parmar, V. 2007. A new late Cretaceous gondwanatherian mammal from central India. Proceedings of the Indian National Science Academy 73(1):17–24.
*Wilson, G.P., Das Sarma, D.C. and Anantharaman, S. 2007. [http://www.bioone.org/doi/pdf/10.1671/0272-4634(2007)27%5B521%3ALCSGFI%5D2.0.CO%3B2 Late Cretaceous sudamericid gondwanatherians from India with paleobiogeographic considerations of Gondwanan mammals] (subscription required). Journal of Vertebrate Paleontology 27(2):521–531.

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[[Category:Maevarano fauna]]
[[Category:Cretaceous mammals]]
[[Category:Fossil taxa described in 1997]]
[[Category:Gondwanatheria]]
[[Category:Prehistoric animals of Madagascar]]
[[Category:Taxa named by David W. Krause]]
[[Category:Taxa named by Guntupalli Veera Raghavendra Prasad]]
[[Category:Taxa named by Wighart von Koenigswald]]
[[Category:Taxa named by Ashok Sahni]]
[[Category:Taxa named by Frederick E. Grine]]