Advertisement

Journal of Mammalian Evolution

, Volume 24, Issue 2, pp 179–191 | Cite as

Baraguatherium takumara, Gen. et Sp. Nov., the Earliest Mylodontoid Sloth (Early Miocene) from Northern South America

  • Ascanio D. Rincón
  • Andrés Solórzano
  • H. Gregory McDonald
  • Mónica Núñez Flores
Original Paper

Abstract

We report a new genus and species of sloth, based on a partial mandible and associated femur, from the early Miocene of Venezuela. Baraguatherium takumara, gen. et sp. nov., represents the earliest member of the Mylodontoidea recognized from northern South America. Phylogenetically and morphologically, Baraguatherium possesses some plesiomorphic characters: a vasodentine layer in the core of the tooth similar to Octodontotherium, Paroctodontotherium, and Orophodon; molariforms parallel to the long axis of the toothrow; teeth with a very thin layer of cementum; mf1-mf3 series of similar size and bilobate; mf3 conspicuously piriform; and occlusal surface of tooth beveled, which places it at the base of the Mylodontidae clade. Baraguatherium was found in continental deposits that also preserve abundant wood and leaves associated with a near shore marine complex, indicating that Baraguatherium lived in a coastal tropical forest in the early Miocene in northern South America. The presence of a vasodentine layer in the core of the tooth is quite similar to Octodontotherium, Paroctodontotherium, and Orophodon and allows assignment of this new taxon to the Mylodontoidea.

Keywords

Baraguatherium takumara Castillo Formation Early miocene Venezuela Sloth diversity 

Notes

Acknowledgments

We wish to thank the Instituto del Patrimonio Cultural (IPC), Venezuela, for fossil collection permissions to this project. We thank Sr. P. Gómez†, Ing. M.E. Mendoza, Lic. M. López, and Dr. F. Urbani for their help and camaraderie during the field trips. The major funding support of this work was provided by Centro de Ecología, Instituto Venezolano de Investigaciones Científicas (IVIC) grant 1096 to A.D.R. Also, we thank to B. Shockey and an anonymous reviewer for all the improvements to that manuscript.

References

  1. Bargo MS, Toledo N, Vizcaíno SF (2012) Paleobiology of the Santacrucian sloths and anteaters (Xenarthra, Pilosa). In: Vizcaíno SF, Kay RF, Bargo MS (eds) Early Miocene Paleobiology in Patagonia: High-latitude Paleocommunities of the Santa Cruz Formation. Cambridge University Press, Cambridge, pp 216–242Google Scholar
  2. Brochu CA, Rincón AD (2004) A gavialoid crocodylian from the lower Miocene of Venezuela. Special Papers in Palaeontology 71:61–79Google Scholar
  3. Carlini AA, Brandoni D, Sánchez-Villagra MR (2006) First megatherines (Xenarthra, Phyllophaga, Megatheriidae) from the urumaco (late Miocene) and codore (Pliocene) formations, Estado Falcón, Venezuela. J Syst Palaeontol 4:269–278. doi: 10.1017/s1477201906001878
  4. Carlini AA, Scillato-Yané GJ (2004) The oldest Megalonychidae (Xenarthra: Tardigrada): phylogenetic relationships and an emended diagnosis of the family. Neu Jb Geol Paläontol Mh 233:423–443Google Scholar
  5. Carlini AA, Vizcaíno SF, Scillato-Yané GJ (1997) Armored xenarthrans: a unique taxonomic and ecologic assemblage. In: Kay RF, Madden RH, Cifelli RL, Flynn JJ (eds) Vertebrate Paleontology in the Neotropics, the Miocene Fauna of La Venta. Smithsonian Institution Press, Washington D. C., pp 213–226Google Scholar
  6. Collins RL (1934) Venezuelan Tertiary mammals. Stud Geol 11:235–244Google Scholar
  7. Cozzuol MA (2006) The acre vertebrate fauna: age, diversity, and geography. J South Am Earth Sci 21:185–203. doi: 10.1016/j.jsames.2006.03.005
  8. Croft DA, Flynn JJ, Wyss AR (2004) Notoungulata and Litopterna of the early Miocene Chucal fauna, northern Chile. Fieldiana Geol 50:1–52Google Scholar
  9. Croft DA, Flynn JJ, Wyss AR (2007) A new basal glyptodontid and other Xenarthra of the early Miocene Chucal fauna, northern Chile. J Vertebr Paleontol 27:781–797. doi: 10.1671/0272-4634(2007)27[781:ANBGAO]2.0.CO;2
  10. Delsuc F, Catzeflis FM, Stanhope MJ, Douzery EJP (2001) The evolution of armadillos, anteaters and sloths depicted by nuclear and mitochondrial phylogenies: implications for the status of the enigmatic fossil Eurotamandua. Proc R Soc Lond B 268:1605–1615Google Scholar
  11. Dozo MT, Ciancio M, Bouza P, Martínez G (2014) Nueva asociación de mamíferos del Paleógeno en el este de la Patagonia (provincia de Chubut, Argentina): implicancias biocronológicas y paleobiogeográfica. Andean Geol 41:224–247. doi: 10.5027/andgeoV41n1-a09
  12. Engelmann GF (1985) The phylogeny of the Xenarthra. In: Montgomery GG (ed) The Evolution and Ecology of Armadillos, Sloths and Vermilinguas. Smithsonian Institution Press, Washington, D.C., pp 51–64Google Scholar
  13. Engelmann GF (1987) A new deseadan sloth (Mammalia: Xenarthra) from Salla, Bolivia, and its implications for the primitive condition of the dentition in edentates. J Vertebr Paleontol 7:217–223Google Scholar
  14. Flynn JJ, Swisher CC (1995) South American land mammal ages: correlation to global geochronologies. In: Berggren WA (ed) Geochronology, Time Scales and Global Stratigraphic Correlation. Society for Sedimentary Geology, Special Publication 54, pp 317–333Google Scholar
  15. Gaudin TJ (1995) The ear region of edentates and the phylogeny of the Tardigrada (Mammalia, Xenarthra). J Vertebr Paleontol 15:672–705 doi: 10.1080/02724634.1995.10011255
  16. Gaudin TJ (2004) Phylogenetic relationships among sloths (Mammalia, Xenarthra, Tardigrada): the craniodental evidence. Zool J Linn Soc 140:255–305 doi: 10.1111/j.1096-3642.2003.00100.x
  17. Gaudin TJ, Croft DA (2015) Paleogene Xenarthra and the evolution of South American mammals. J Mammal 96:622–634 doi: 10.1093/jmammal/gyv073
  18. Goin FJ, Chornogubsky L, Gelfo JN, Woodburne MO, Martin T (2012) Origins, radiations, and distribution of South American mammals: from greenhouse to icehouse worlds. In: Patterson BD, Costa LP (eds) Bones, Clones, and Biomes: an 80-million Year History of Recent Neotropical mammals. University of Chicago Press, Chicago, pp 20–50 doi: 10.7208/chicago/9780226649214.003.0003
  19. Goloboff P, Farris J, Nixon K (2008) TNT, a free program for phylogenetic analysis. Cladistics 24:774–786 doi: 10.1111/j.1096-0031.2008.00217.x
  20. Green JL, Kalthoff DC (2015) Xenarthran dental microstructure and dental microwear analyses, with new data for Megatherium americanum (megatheriidae). J Mammal 96:645–657 doi: 10.1093/jmamma/gyv045
  21. Guilherme E, Bocquentin J, Porto AS (2011) A new specimen of the genus Octodontobradys (Orophodontidae, Octodontobradyinae) from the late Miocene-Pliocene of the southwestern Amazon Basin, Brazil. Anuário do Instituto de Geociências 34:38–45Google Scholar
  22. Hirschfeld SE (1985) Ground sloths from the Friasian La Venta Fauna, with additions to the pre-Friasian Coyaima Fauna of Colombia, South America. Univ Calif Publ Geol Sci 128:1–91Google Scholar
  23. Hoffstetter R (1954) Les gravigrades cuirassés du Déséadien de patagonie. Mammalia 18:159–169Google Scholar
  24. Hoffstetter R (1956) Contribution a l’étude des Orophodontoidea gravigrades cuirassés de la patagonie. Ann Paléontol 42:27–64Google Scholar
  25. Hoffstetter R (1969) Remarques sur la phylogénie et la classification des Edentés Xénarthres (Mammifères) actuels et fossiles. Bull Mus His Nat 41:91–103Google Scholar
  26. Hoffstetter R (1982) Les Edentés Xénarthres, un group singular de la faune néotropicale (origine, affinités, radiation, adaptative, migrations, extinctions). In: Montanaro Gallitelli (ed) Paleontology, Essentials of Historical Geology. S.T.E.M. Mucchi, Modena, pp 385–443Google Scholar
  27. Johnson K, Sánchez-Villagra M, Aguilera OA (2009) The Oligocene-Miocene transition on coral reefs in the Falcón Basin (NW Venezuela). Palaios 24:59–69. doi: 10.2110/palo.2008.p08-004r
  28. Linares OJ (2004) Bioestratigrafía de la fauna de Mamíferos de las formaciones Socorro, urumaco y codore (mioceno medio- plioceno temprano) de la región de urumaco, Falcón, Venezuela. Paleobiol Neotrop (Caracas) 1:1–26Google Scholar
  29. Marshall LG, Drake RE, Curtis GH, Butler RF, Flanagan KM, Naeser CW (1986) Geochronology of type Santacrucian (middle Tertiary) land mammal age, Patagonia, Argentina. J Geol 94:449–457. doi: 10.1086/629050
  30. McDonald HG (1997) Xenarthrans: pilosans. In: Kay RF, Madden RH, Cifelli RL, Flynn JJ (eds) Vertebrate Paleontology in the Neotropics, the Miocene Fauna of La Venta. Smithsonian Institution Press, Washington, D.C., pp 231–243Google Scholar
  31. McDonald HG (2003) Xenarthran skeletal anatomy: primitive or derived? In: Fariña RA, Vizcaíno SF, Storch G (eds) Morphological Studies in Fossil and Extant Xenarthra (Mammalia). Senckenbergiana biologica 83, pp 1–13Google Scholar
  32. McDonald HG (2005) Paleoecology of extinct xenarthrans and the great American biotic interchange. Bull Florida Mus Nat His 45:313–333Google Scholar
  33. McDonald HG, De Iuliis G (2008) Fossil history of sloths. In: Vicaíno SF, Loughry WJ (eds) Biology of the Xenarthra. University Press of Florida, Gainesville, pp 39–55Google Scholar
  34. McKenna MC, Bell SK (1997) Classification of Mammals above the Species Level. Columbia University Press, New YorkGoogle Scholar
  35. McKenna MC, Wyss AR, Flynn JJ (2006) Paleogene pseudoglyptodont xenarthrans from Central Chile and Argentine Patagonia. Am Mus Novitates 3536:1–18. doi: 10.1206/0003-0082(2006)3536[1:ppxfcc]2.0.co;2
  36. Mones A (1986) Palaeovertebrata sudamericana. catalogo sistemático de los vertebrados fósiles de América del sur. parte I. lista preliminar y bibliografía. Courier Forschungsinstitut Senckenberg 82:1–625Google Scholar
  37. Muizon C de, McDonald HG (1995) An aquatic sloth from the Pliocene of Peru. Nature 375:224–227. doi: 10.1038/375224a0
  38. Negri FR, Bocquentin-Villanueva J, Ferigolo J, Pierre-Olivier A (2010) A review of Tertiary mammal faunas and birds from western Amazonia. In: Hoorn C, Wesselingh H (eds) Amazonia, Landscape and Species Evolution, a Look into the Past. Wiley-Blackwell, Oxford, pp 245–258. doi: 10.1002/9781444306408.ch15
  39. Oramas L (1916) Materiales para el estudio de los dialectos ayaman, Oayón, jirajara, ajagua. Litografía de Comercio, CaracasGoogle Scholar
  40. Pujos F, De Iuliis G (2007) Late Oligocene Megatherioidea fauna (Mammalia: Xenarthra) from Salla-Luribay (Bolivia): new data on basal sloth radiation and Cingulata-Tardigrada split. J Vertebr Paleontol 27:132–144. doi: 10.1671/0272-4634(2007)27[132:LOMFMX]2.0.CO;25
  41. Rincón AD, McDonald HG, Solórzano A, Núñez Flores M, Ruiz-Ramoni D (2015) A new enigmatic late Miocene mylodontoid sloth from northern South America. R Soc Open Sci 2:140256. Doi: 10.1098/rsos.r140256
  42. Rincón AD, Solórzano A, Benammi M, Vignaud P, McDonald HG (2014) Chronology and geology of an early Miocene mammalian assemblage in north of South America, from Cerro La Cruz (Castillo Formation), Lara State, Venezuela: implications in the ‘changing course of Orinoco River’ hypothesis. Andean Geol 41:507–528. doi: 10.5027/andgeoV41n3-a02
  43. Rinderknecht A, Bostelmann E, Perea D, Lecuona G (2010) A new genus and species of Mylodontidae (Mammalia: Xenarthra) from the late Miocene of southern Uruguay, with comments on the systematics of the Mylodontinae. J Vertebr Paleontol 30:899–910. doi: 10.1080/02724631003757997.
  44. Sánchez-Villagra M, Asher RJ, Rincón AD, Carlini AA, Meylan P, Purdy RW (2004) New faunal reports for the Cerro La Cruz locality (lower Miocene, northwestern Venezuela). Special Papers in Palaeontology 71:105–116Google Scholar
  45. Santos JCR, Rancy A, Ferigolo J (1993) Octodontobradyinae, uma nova subfamília de Orophodontidae (Edentata, Tardigrada) do mioceno superior-plioceno do Estado do Amazonas, brasil. Ameghiniana 30:255–264Google Scholar
  46. Scillato-Yané GJ (1977) Octomylodontinae: nueva subfamilia de Mylodontidae (Edentata, Tardigrada). Descripción del cráneo y mandíbula de Octomylodon robertoscagliai n. sp., procedentes de la Formación Arroyo Chasicó (Edad Chasiquense, Plioceno Temprano) del sur de la Provincia de Buenos Aires (Argentina): Algunas consideraciones filogenéticas y sistemáticas sobre los Mylodontoidea. Publicaciones del Museo de Ciencias Naturales de Mar del Plata ‘Lorenzo Scaglia’ 2:123–140Google Scholar
  47. Scott KM (1990) Postcranial dimensions of ungulates as predictors of body mass. In: Damuth J, MacFadden BJ (eds) Body Size in Mammalian Paleobiology: Estimation and Biological Implications, Cambridge University Press, New York, pp 331–335Google Scholar
  48. Shockey BJ, Anaya F (2010) Grazing in a new late Oligocene mylodontid sloth and a mylodontid radiation as a component of the Eocene-Oligocene faunal turnover and the early spread of grasslands/savannas in South America. J Mammal Evol 18:101–115. doi: 10.1007/s10914-010-9147-5
  49. Toledo N, Cassini GH, Vizcaíno SF, Bargo MS (2014) Mass estimation of Santacrucian sloths from the early Miocene Santa Cruz Formation of Patagonia, Argentina. Acta Palaeontol Pol 59:267–280. doi: 10.4202/app.2012.0009
  50. Villarroel CA (2000) Un Nuevo Mylodontinae (Xenarthra, Tardigrada) en la fauna de La Venta, mioceno de Colombia: el estado actual de la familia orophodontoidae. Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales 24:117–127Google Scholar
  51. Wheeler CB (1960) Estratigrafía del Oligoceno y Mioceno inferior de Falcón occidental y nororiental. In: Congreso Geológico Venezolano No. 3 (Memorias 1), Caracas, pp 407–465Google Scholar
  52. White JL (1997) Locomotor adaptations in Miocene xenarthrans. In: Kay RF, Madden RH, Cifelli RL, Flynn JJ (eds) Vertebrate Paleontology in the Neotropics, the Miocene Fauna of La Venta. Smithsonian Institution Press, Washington, D.C., pp 246–264Google Scholar
  53. Wilson DE, Reeder DM (2005) Mammal Species of the World: A Taxonomic and Geographic Reference, 3rd ed. Smithsonian Institution Press, Washington, D.C.Google Scholar
  54. Woodburne MO (2010) The great American biotic interchange: dispersals, tectonics, climate, sea level and holding pens. J Mammal Evol 17:245–264. doi: 10.1007/s10914-010-9144-8
  55. Wyss AR, Norell MA, Flynn JJ, Novacek MJ, Charrier R, McKenna MC, Swisher III CC, Frassinetti D, Salinas P, Jin M (1990) A new Tertiary mammal fauna from Central Chile: implications for Andean stratigraphy and tectonics. J Vertebr Paleontol 10:518–522. doi: 10.1080/02724634.1990.10011835

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • Ascanio D. Rincón
    • 1
  • Andrés Solórzano
    • 1
  • H. Gregory McDonald
    • 2
  • Mónica Núñez Flores
    • 1
  1. 1.Laboratorio de Paleontología–Centro de EcologíaInstituto Venezolano de Investigaciones Científicas (IVIC)CaracasVenezuela
  2. 2.Bureau of Land Management, Utah State OfficeSalt Lake CityUSA

Personalised recommendations