Journal of Mammalian Evolution

, Volume 25, Issue 3, pp 327–337 | Cite as

New Remains of Megathericulus patagonicus Ameghino, 1904 (Xenarthra, Tardigrada) from the Serravallian (Middle Miocene) of Bolivia; Chronological and Biogeographical Implications

  • Diego Brandoni
  • Alfredo A Carlini
  • Federico Anaya
  • Phil Gans
  • Darin A Croft
Original Paper


In this contribution, we describe new remains (skull and humeri) of the Megatheriinae Megathericulus patagonicus Ameghino, 1904, recovered from the middle Miocene fossiliferous locality of Quebrada Honda, Bolivia. We also discuss the taxonomic, biogeographical, and chronological relevance of this discovery. Referral of the new specimens described here to Megathericulus patagonicus is based on metric and morphological similarities with the holotype and a humerus that has been referred to this species. Shared features include: 1) molariforms that are mesiodistally compressed and rectangular in outline; 2) a relatively less compressed M1 with labial and lingual margins that converge slightly mesially; 3) a very long premolariform portion of the maxillae (rostrum); 4) anteriorly divergent lateral edges of the maxillae; 5) a prominent, median V-shaped notch (apex posterior) between the articular surfaces of the maxillae and premaxillae; and 6) a long, gracile humerus with a prominent anterolaterally positioned deltopectoral crest on the anterior surface and a clearly evident lateral musculo-spiral channel. Precise geographic and stratigraphic data exist for the described remains, which are closely associated with a tuff dated at 12.2–12.5 Ma (Serravallian, middle Miocene), making it the first accurately dated specimen referred to Megathericulus Ameghino, 1904.


Megatheriinae Folivora South America Ground sloths 40Ar/39Ar dating U-Pb dating 



For assistance in the field and geological observations, we thank K. Bamba, M. Ciancio, A. Deino, L. Gibert, F. Mamani, O. Moreira, B. Saylor, B. Shockey, and E. Vilca. Comments and suggestions of two reviewers and the editors improved this manuscript. This research was supported by the National Geographic Foundation (NGS 8115-06 to DAC) and the National Science Foundation (EAR 0958733 and 1423058 to DAC).


  1. Ameghino C, Kraglievich L (1921) Descripción del “Megatherium gallardoi” C. Amegh. descubierto en el Pampeano inferior de la ciudad de Buenos Aires. Anales del Museo Nacional de Historia Natural de Buenos Aires 31: 134–156Google Scholar
  2. Ameghino F (1887) Enumeración sistemática de las especies de mamíferos fósiles coleccionados por Carlos Ameghino en los terrenos eocenos de la Patagonia austral y depositados en el Museo La Plata. Boletín del Museo de La Plata 1: 1–26Google Scholar
  3. Ameghino F (1904) Nuevas especies de mamíferos cretáceos y terciarios de la República Argentina. Anales de la Sociedad Científica Argentina 58: 225–291Google Scholar
  4. Amson E, Muizon C de, Gaudin TJ (2016) A reappraisal of the phylogeny of the Megatheria (Mammalia: Tardigrada), with an emphasis on the relationships of the Thalassocninae, the marine sloths. Zool J Linn Soc doi:  10.1111/zoj.12450
  5. Bengtson P (1988) Open nomenclature. Palaeontology 31: 223–227Google Scholar
  6. Bondesio P, Rabassa J, Pascual R, Vucetich MG, Scillato-Yané GJ (1980) La Formación Collón-Curá de Pilcaniyeu Viejo y sus alrededores (Río Negro, República Argentina). Su antigüedad y las condiciones ambientales según su distribución, su litogénesis y sus vertebrados. Actas II Congreso Argentino de Paleontología y Bioestratigrafía y I Congreso Latinoamericano de Paleontología 3: 85–99. Buenos Aires, Argentina, 1978Google Scholar
  7. Brandoni D (2006) Los Megatheriinae (Xenarthra, Tardigrada, Megatheriidae) Terciarios de la Argentina. Sistemática, Evolución y Biogeografía. Tesis Doctoral. Facultad de Ciencias naturales y Museo, Universidad Nacional de La Plata, 392 ppGoogle Scholar
  8. Brandoni D (2014) “Xyophorus” sp. en el Mioceno Medio de Chubut: implicancias sistemáticas, biogeográficas y biocronológicas del registro de un Nothrotheriinae en el Neógeno de la Argentina. Ameghiniana 51: 94–105CrossRefGoogle Scholar
  9. Brandoni D, Carlini AA (2009) On the presence of Pyramiodontherium (Mammalia, Tardigrada, Megatheriidae) in the “Conglomerado osífero” (late Miocene) of Argentina and its biogeographical implications. Riv Ital Paleontol Stratigr 115: 111–123Google Scholar
  10. Brandoni D, De Iuliis G (2007) A new genus for the Megatheriinae (Xenarthra, Phyllophaga, Megatheriidae) from the Arroyo Chasicó Formation (upper Miocene) of Buenos Aires Province, Argentina. Neues Jahrb Geol Palaontol Abh 244: 53–64CrossRefGoogle Scholar
  11. Brandoni D, Powell JE, González OE (2012) Anisodotherium from the late Miocene of north-western Argentina. Acta Palaeontol Pol 57: 241–249Google Scholar
  12. Brandoni D, Scillato-Yané GJ (2007) Los Megatheriinae (Xenarthra, Tardigrada) del Terciario de Entre Ríos, Argentina: aspectos taxonómicos y sistemáticos. Ameghiniana 44: 427–434Google Scholar
  13. Burmeister H (1891) Continuación a las adiciones al examen crítico de los mamíferos terciarios. Anales del Museo Nacional de Buenos Aires 3: 401–461Google Scholar
  14. Cabrera A (1928) Sobre algunos megaterios pliocenos. Revista del Museo de La Plata 31: 339–352Google Scholar
  15. Cabrera A (1939) Un nuevo representante Santacrucense de la Familia Megatheriidae. Notas del Museo de La Plata, Paleontología 4: 475–483Google Scholar
  16. Cadena EA, Anaya F, Croft DA (2015) Giant fossil tortoise and freshwater chelid turtle remains from the middle Miocene, Quebrada Honda, Bolivia: evidence for lower paleoelevations for the southern Altiplano. J S Am Earth Sci 64: 190–198CrossRefGoogle Scholar
  17. Carlini AA, Brandoni D, Dal Molin CN (2013) A new genus and species of Planopinae (Xenarthra: Tardigrada) from the Miocene of Santa Cruz Province, Argentina. Zootaxa 3694 6: 565-578Google Scholar
  18. Carlini AA, Brandoni D, Sánchez R (2006) First megatheriines (Xenarthra, Phyllophaga, Megatheriidae) from the Urumaco (late Miocene) and Codore (Pliocene) formations, Estado Falcón, Venezuela. J Syst Palaeontol 4: 269–278CrossRefGoogle Scholar
  19. Carlini AA, Brandoni D, Scillato-Yané GJ, Pujos F (2002a) Una nueva especie de megaterino (Xenarthra, Megatheriidae) del Mioceno Tardío-Plioceno de Catamarca, Argentina. Ameghiniana 39: 367–377Google Scholar
  20. Carlini AA, Scillato-Yané GJ, Brandoni D, (2002b) Un nuevo tardígrado (Mammalia, Xenarthra) del Mioceno Medio de Quebrada Honda, Bolivia: el más antiguo Megatheriinae? VIII Congreso Argentino de Paleontología y Bioestratigrafía, Resúmenes: 98, CorrientesGoogle Scholar
  21. Cope ED (1889) The Edentata of North America. Am Nat 23: 657–664CrossRefGoogle Scholar
  22. Croft DA (2007) The middle Miocene (Laventan) Quebrada Honda Fauna, southern Bolivia, and a description of its notoungulates. Palaeontology 50: 277–303CrossRefGoogle Scholar
  23. Croft DA, Anaya F, Auerbach D, Garzione C, MacFadden BJ (2009) New data on Miocene Neotropical provinciality from Cerdas, Bolivia. J Mammal Evol 16: 175–198CrossRefGoogle Scholar
  24. Croft DA, Carlini AA, Ciancio MR, Brandoni D, Drew NE, Engelman RK, Anaya F (2016) New mammal faunal data from Cerdas, Bolivia, a mid-latitude Neotropical site that chronicles the end of the middle Miocene climatic optimum in South America. J Vertebr Paleontol 36: e1163574CrossRefGoogle Scholar
  25. Croft DA, Chick J, Anaya F (2011) New middle Miocene caviomorph rodents from Quebrada Honda, Bolivia. J Mammal Evol 18: 245–268CrossRefGoogle Scholar
  26. Cuvier G (1796) Notice sur le squelette d’une très-grande espèce de quadrupède inconue jusqu’à présent trouvé au Paraguay, et déposé au cabinet d’histoire naturelle de Madrid. Magasin Encyclopèdique: ou Journal des Sciences, des Lettres et des Arts 1: 303–310; 2: 227–228Google Scholar
  27. Dal Molin CN, Franchi M (1996) Reinterpretación estratigráfica de las sedimentitas terciarias del suroeste de Chubut. XIII Congreso Geológico Argentino y III Congreso de Exploración de Hidrocarburos, Actas 1: 473–478. Buenos Aires.Google Scholar
  28. De Iuliis G (1994) Relationships of the Megatheriinae, Nothrotheriinae, and Planopsinae: some skeletal characteristics and their importance for phylogeny. J Vertebr Paleontol 14: 577–591Google Scholar
  29. De Iuliis G (1996) A systematic review of the Megatheriinae (Mammalia: Xenarthra: Megatheriidae). Unpublished Doctoral Thesis, University of Toronto, Toronto, 781 ppGoogle Scholar
  30. De Iuliis G (2006) On the taxonomic status of Megatherium sundti Philippi, 1893 (Mammalia: Xenarthra: Megatheriidae). Ameghiniana 43: 161–169Google Scholar
  31. De Iuliis G, Brandoni D, Scillato-Yané GJ (2008) New remains of Megathericulus patagonicus Ameghino 1904 (Xenarthra, Megatheriidae): information on primitive features of megatheriines. J Vertebr Paleontol 28: 181–196.CrossRefGoogle Scholar
  32. De Iuliis G, Pujos F, Tito G (2009) Systematic and taxonomic revision of the Pleistocene ground sloth Megatherium (Pseudomegatherium) tarijense (Xenarthra: Megatheriidae). J Vertebr Paleontol 29: 1244–1251CrossRefGoogle Scholar
  33. De Iuliis G, Ré GH, Vizcaíno SF (2004) The Toro negro megatheriine (Mammalia: Xenarthra): a new species of Pyramiodontherium and a review of Plesiomegatherium. J Vertebr Paleontol 24: 214–227CrossRefGoogle Scholar
  34. De Iuliis G, Saint-André PA (1997) Eremotherium sefvei nov. sp. (Mammalia: Xenarthra: Megatheriidae) from the Pleistocene of Ulloma, Bolivia. Geobios 30: 453-461Google Scholar
  35. Engelman RK, Anaya F, Croft DA (2015) New specimens of Acyon myctoderos (Metatheria, Sparassodonta) from Quebrada Honda, Bolivia. Ameghiniana 52: 204–225CrossRefGoogle Scholar
  36. Engelman RK, Croft DA (2014) A new small-bodied sparassodont (Mammalia, Metatheria) from the middle Miocene locality of Quebrada Honda, Bolivia. J Vertebr Paleontol 34: 672–688CrossRefGoogle Scholar
  37. Forasiepi AM, Sánchez-Villagra MR, Goin FJ, Taka M, Shigehara N, Kay RF (2006) A new species of Hathliacynidae (Metatheria, Sparassodonta) from the middle Miocene of Quebrada Honda, Bolivia. J Vertebr Paleontol 26: 670–684CrossRefGoogle Scholar
  38. Gaudin TJ (2004) Phylogenetic relationships among sloths (Mammalia, Xenarthra, Tardigrada): the craniodental evidence. Zool J Linn Soc 140: 255–305CrossRefGoogle Scholar
  39. Gradstein FM, Ogg JG, Schmitz M, Ogg G (2012) The Geologic Time Scale 2012. Elsevier Science Ltd, Oxford, 1176 ppGoogle Scholar
  40. Gray JE (1821) On the natural arrangement of vertebrose animals. London Medical Repository 5: 296–310Google Scholar
  41. Hoffstetter R (1977) Un gisement de mammifères miocènes à Quebrada Honda (Sud Bolivien). CR Acad Sci D 284: 1517–1520Google Scholar
  42. Kraglievich L (1930) La formación friaseana del Río Frías, Río Fénix, Laguna Blanca, etc. y su fauna de mamíferos. Physis 10: 127–161Google Scholar
  43. Latham J, Davies H (1795) Faunula indica, 38 pp. Appendix to Forster JR. 2nd edition, Gebauer JJ, Halle a.S.Google Scholar
  44. Lund PW (1842) Blik paa Brasiliens Dyreverden for Sidste Jordomvaeltning. Fjerde Afhandling: Fortsaettelse af Pattedyrene. Detkongelige Danske Videnscabernes Selskabs Skrifter; Naturvidenskabelige og Mathematisk Afhandlinger 9: 137–208Google Scholar
  45. MacFadden BJ, Anaya F, Perez H, Naeser CW, Zeitler PK, Campbell KE Jr (1990) Late Cenozoic paleomagnetism and chronology of Andean basins of Bolivia: evidence for possible oroclinal bending. J Geol 98: 541–555CrossRefGoogle Scholar
  46. Madden R H, Guerrero J, Kay RF, Flynn JJ, Swisher CC III, Walton AH (1997) The Laventan stage and age. In: Kay RF, Madden RH, Cifelli RL, Flynn JJ (eds), Vertebrate Paleontology in the Neotropics: the Miocene Fauna of La Venta, Colombia. Smithsonian Institution Press, Washington, D.C., pp 499–519Google Scholar
  47. Moreno FP, Mercerat A (1891) Exploración arqueológica de la Provincia de Catamarca: Paleontología. Revista del Museo de La Plata 1: 222–236Google Scholar
  48. Muizon C. de, McDonald HG (1995) An aquatic sloth from the Pliocene of Peru. Nature 375: 224–227Google Scholar
  49. Ogg JG (2012) Geomagnetic polarity time scale. In: Gradstein FM, Ogg JG, Schmitz M, Ogg G (eds), The Geologic Time Scale 2012. Elsevier, New York, pp 85–113CrossRefGoogle Scholar
  50. Pujos F (2006) Megatherium celendinense sp. nov. from the Pleistocene of Peruvian Andes and the megatheriine phylogenetic relationship. Palaeontology 49: 285–306CrossRefGoogle Scholar
  51. Pujos F, De Iuliis G, Mamani Quispe B (2011) Hiskatherium saintandrei, gen. et sp. nov.: an unusual sloth from the Laventan of Quebrada Honda (Bolivia) and an overview of middle Miocene, small megatherioids. J Vertebr Paleontol 31: 1131–1149CrossRefGoogle Scholar
  52. Pujos F, De Iuliis G, Mamani Quispe B, Andrade Flores R (2014) Lakukullus anatisrostratus, gen. et sp. nov., a new massive nothrotheriid sloth (Xenarthra, Pilosa) from the middle Miocene of Bolivia. J Vertebr Paleontol 34: 1243–1248CrossRefGoogle Scholar
  53. Pujos F, Salas-Gismondi R, Baby G, Baby P, Goillot C, Tejada J, Antoine P-O (2013) Implication of the presence of Megathericulus (Xenarthra: Tardigrada: Megatheriidae) in the Laventan of Peruvian Amazonia. J Syst Palaeontol 11: 973–991CrossRefGoogle Scholar
  54. Rovereto C (1914) Los estratos araucanos y sus fósiles. Anales del Museo Nacional de Historia Natural de Buenos Aires 25: 1-247Google Scholar
  55. Saint-André P-A, De Iuliis G (2001) The smallest and most ancient representative of the genus Megatherium Cuvier, 1796 (Xenarthra, Tardigrada, Megatheriidae), from the Pliocene of the Bolivian Altiplano. Geodiversitas 23: 625–645Google Scholar
  56. Scillato-Yané GJ, Carlini AA (1998) Nuevos Xenarthra del Friasense (Mioceno medio) de Argentina. Stvdia Geologica Salmanticensia 34: 43–67Google Scholar
  57. Takai F, Arózqueta B, Mizuno T, Yoshida A, Kondo H (1984) On fossil mammals from the Tarija department, southern Bolivia. The Research Institute of Evolutionary Biology 4:1–63Google Scholar
  58. Tejada-Lara JV, Salas-Gismondi R, Pujos F, Baby P, Benammi M, Brusset S, De Franceschi D, Espurt N, Urbina M, Antoine P-O (2015) Life in proto-Amazonia: middle Miocene mammals from the Fitzcarrald arch (Peruvian Amazonia). Palaeontology 58: 341–378CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2017

Authors and Affiliations

  • Diego Brandoni
    • 1
  • Alfredo A Carlini
    • 2
  • Federico Anaya
    • 3
  • Phil Gans
    • 4
  • Darin A Croft
    • 5
  1. 1.Laboratorio de Paleontología de VertebradosCentro de Investigaciones Científicas y Transferencia de Tecnología a la Producción (CICYTTP-CONICET)DiamanteArgentina
  2. 2.División Paleontología de Vertebrados, Museo de La Plata, Facultad de Ciencias Naturales y MuseoUniversidad Nacional de La PlataLa PlataArgentina
  3. 3.Facultad de Ingeniería GeológicaUniversidad Autónoma Tomás FríasPotosíBolivia
  4. 4.Department of Earth ScienceUniversity of CaliforniaSanta BarbaraUSA
  5. 5.Department of AnatomyCase Western Reserve UniversityClevelandUSA

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