磨齒獸科

磨齒獸科（學名：），又稱磨齒懶科，是已滅絕的地懶，生存於2,300萬至11,000年前的北美洲及南美洲。磨齒獸科與同樣已滅絕的，以及現存樹棲性的二趾樹懶科為近親，三者均屬於磨齒獸總科。磨齒獸科與陵角懶科之間的親緣關係證據主要是來自種系發生學及形態學分析，甚至有部分較早期的研究會將陵角懶科置於磨齒獸科下。而磨齒獸科與二趾樹懶科之間的親緣關係證據則仰賴粒線體DNA及膠原蛋白胺基酸序列的分析研究。後者分析顯示二趾樹懶科比起二趾樹懶科，與磨齒獸科的親緣關係更為接近。此外，同樣仍未滅絕的樹懶科（包含已知的4種三趾樹懶）則是屬於親緣關係較遠的大地懶總科。然而，放射性碳定年法分析顯示人類及地懶生存於洞穴的時間並未有重疊。磨齒獸科是目前已知確認具有皮內成骨的地懶，但僅有部分屬具有此特徵，其中就包括了磨齒獸屬、副磨齒獸屬及，其他屬則缺乏。

系統發生樹
拉普拉塔博物館]]
本系統發生樹係根據膠原蛋白及粒線體DNA序列分析：

{{clade | style = font-size: 100%;line-height:100%
|label1=食葉亞目 Folivora
|1={{clade
|1=加勒比地懶科 Megalocnidae
|2={{clade
|label1=磨齒獸總科 Mylodontoidea
|1=
|label2=大地懶總科 Megatherioidea
|2=
}}
}}
}}

參考文獻
參考書目
Woodward, A.S. (1900): On some remains of Grypotherium (Neomylodon) listai and associated mammals from a cavern near Consuelo Cove, Last Hope Inlet. Proceedings of the Zoological Society of London*, 1900(5): 64–79.

延伸閱讀
*
Cuvier, G. (1796): Notice sur le squelette d'une très grande espèce de quadrupède inconnue jusqu'à présent, trouvé au Paraguay, et déposé au cabinet d'histoire naturelle de Madrid. Magasin encyopédique, ou Journal des Sciences, des Lettres et des Arts* (1): 303–310; (2): 227–228.
De Iuliis, G. & Cartelle, C. (1999): A new giant megatheriine ground sloth (Mammalia: Xenarthra: Megatheriidae) from the late Blancan to early Irvingtonian of Florida. Zool. J. Linn. Soc.* 127(4): 495–515.

• (1993): [https://web.archive.org/web/20031206051103/http://www.beringia.com/02/02maina1.html Yukon Beringia Interpretive Center - Jefferson's Ground Sloth]. Retrieved 2008-JAN-24.

Hogan, C.M. (2008): [http://www.megalithic.co.uk/article.php?sid=18820 Cueva del Milodon*, Megalithic Portal] . Retrieved 2008-APR-13

• (1980): Pleistocene Mammals of North America. Columbia University Press, New York.

McKenna, Malcolm C. & Bell, Susan K. (1997): Classification of Mammals Above the Species Level.* Columbia University Press, New York.
Nowak, R.M. (1999): Walker's Mammals of the World* (Vol. 2). Johns Hopkins University Press, London.
*White, J.L. (1993): Indicators of locomotor habits in Xenarthrans: Evidence for locomotor heterogeneity among fossil sloths. Journal of Vertebrate Paleontology, 13(2): 230–242.
*

外部連結

• Sloth World: An Online Sloth Bibliography
• [https://web.archive.org/web/20070529200608/http://www.libs.uga.edu/science/sloth.html Picture and information about a ground sloth skeleton on display at the University of Georgia's Science Library]
• [https://web.archive.org/web/20060823122149/http://www.acnatsci.org/museum/leidy/paleo/megalonyx.html Academy of Natural Sciences ground sloth page]
• [https://www.museum.state.il.us/exhibits/larson/sloth.html Illinois State Museum ground sloth page]
• [https://web.archive.org/web/20040206222938/http://www.tarpits.org/education/guide/flora/sloth.html Ground sloths at La Brea]
• [https://web.archive.org/web/20060907012851/http://news.ufl.edu/2000/06/20/sloth/ Eremotherium in Florida]
• [http://unmuseum.mus.pa.us/sloth.htm Have some ground sloths survived in Argentina?]
• [https://web.archive.org/web/20031206051103/http://www.beringia.com/02/02maina1.html Ground sloths in general]
• [http://www.westerncentermuseum.org Western Center for Archaeology and Paleontology] Hemet, CA