The alleged astragalar remains of Didolodus Ameghino, 1897 (Mammalia, Panameriungulata) and a critic of isolated bone association models

 

Authors: Gelfo JN, Lorente M

Published in: Bulletin of Geosciences, volume 87, issue 2; pages: 249 - 259; Received 13 July 2011; Accepted in revised form 16 December 2011; Online 14 March 2012

Keywords: South America, Paleogene, Didolodontidae, astragali, regression equation models,

full text (PDF, 0.79 MB)

Export to RIS

 

Abstract

Postcranial characters of South American native ungulates are important in order to analyze their relationships in the actual therian taxonomy, particularly to test their alleged afrotherian affinities. In this sense, the most primitive and oldest South American eutherians are represented by two endemic groups of “condylarths”, the Kollpaniinae and Didolodontidae. These forms, characterized by lower crowned bunodont dentition, have never been found in direct association with their postcranial remains. Even though, several skeletal elements have been assigned to some of forms, following different assumptions and criteria. Two distinct astragalar remains (MACN-CA 10737 and AMNH 117457) have been referred to the genus Didolodus, one of the most common didolodontids from early and middle Eocene Patagonian outcrops. Here we describe in detail and illustrate these materials. A critical analysis is made of several regression equation models which have been used in other cases to associate by size isolated postcranial elements to taxa defined by teeth. A new model was formulated based on 19 modern bunodont mammals with directly associated skeletons in order to test the accuracy of the regression equations. Although the results of the equation models failed to accuratly assigned the isolated astragali to any of the Didolodus species, they can be used as a good tool to disprove the association hypothesis. A broad comparison with astragalar remains of South American native ungulates indicates that MACN-CA 10737 has notoungulate affinities, in contrast AMNH 117457 resembles the astragali assigned to didolodontids from Sao José de Itaboraí, Brazil, according to the models criticized here. The similitude is particularly due to the broad development of the cotylar fossa, a character proposed as an afrotherian synapomorphy, but probably developed independently in different groups. Improvement in knowledge regarding postcranial characters of the earliest South American native ungulates is necessary not only due to its importance in improving accuracy of phylogenetic relationships, but also for the inferences made on paleobiological features.

References

Agnolin, F.L. & Chimento, N.R. 2011. Afrotherian affinities for endemic South American “ungulates”. Mammalian Biology 76, 101–108.

Ameghino, F. 1904. La perforación astragaliana en los mamíferos no es un carácter originariamente primitivo. Anales del Museo Nacional de Buenos Aires 4, 349–460.

Asher, R.J. & Lehmann, T. 2008. Dental eruption in afrotherian mammals. BMC Biology 6, 14.View article

Benedetto, J.L. 2010. El continente de Gondwana a través del tiempo, una introducción a la geología histórica. 384 pp. Academia Nacional de Ciencias, Córdoba, Argentina.

Bergqvist, L.P. 1996. Reassociaçao do pós-crânio as espécies de ungulados da bacia de S. J. de Itaboraí (Paleoceno), Estado do Rio de Janeiro, e filogenia dos “Condylarthra” e ungulados sul-americanos com base no pós-crânio. 407 pp. Ph.D. thesis, Universidade Federal do Rio Grande do Sul, Rio Grande do Sul, Brazil.

Bergqvist, L.P. 2008. Postcranial skeleton of the Upper Paleocene (Itaboraian) “Condylarthra” (Mammalia) of Itaboraí Basin, Brazil, 107–133. In Sargis, E.J. & Dagosto, M. (eds) Mammalian Evolutionary Morphology. A tribute to Frederik S. Szalay. Springer-Verlag, New York.View article

Billet, G. & Thomas, M. 2011. No evidence for an afrotherian-like delayed dental eruption in South American notoungulates. Naturwissenschaften 98(6), 509–517.View article

Cifelli, R.L. 1983a. Eutherian tarsals from the late Paleocene of Brazil. American Museum Novitates 2761, 1–31.

Cifelli, R.L. 1983b. The origin and affinities of the South American Condylarthra and early Tertiary Litopterna (Mammalia). American Museum Novitates 2772, 1–49.

Cifelli, R.L. 1993. The Phylogeny of the Native South American Ungulates 1, 195–216. In Szalay, F.S., Novacek, M.J. & McKenna, M.C. (eds) Mammal Phylogeny (2 volumes). Springer Verlag, New York.

Cifelli, R.L. & Villarroel, C. 1997. Paleobiology and affinities of Megadolodus, 265–288. In Kay, R., Madden, R.H., Cifelli, R.L. & Flynn, J.J. (eds) Vertebrate paleontology in the Neotropics: The Miocene fauna of La Venta. Colombia Smithsonian Institution Press, Washington & Londres.

Damuth, J. 1990. Problems in estimating body masses of archaic ungulates using dental measures, 229–254. In Damuth, J. & MacFadden, B.J. (eds) Body size in mammalian paleobiology. Cambridge University Press, Cambridge.

Damuth, J. & MacFadden, B.J. (eds) 1990. Body size in mammalian paleobiology. 397 pp. Cambridge University Press, Cambridge.

Gelfo, J.N. 2006. Los Didolodontidae (Mammalia, Ungulatomorpha) del Terciario Sudamericano. Sistemática, Origen y evolución. 465 pp. Ph.D. thesis, Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata, La Plata, Argentina.

Gelfo, J.N. 2010. The “Condylarth” Didolodontidae from Gran Barranca: History of the Bunodont South American mammals until the Eocene-Oligocene transition. In Madden, R.H., Carlini, A.A.,Vucetich, M.G.&Kay, R.F. (eds) The Paleontology of Gran Barranca: Evolution and Environmental Change through the Middle Cenozoic of Patagonia. Cambridge University Press, Cambridge.

Gelfo, J.N., Goin, F.J., Woodburne, M. & Muizon, C. De 2009. Biochronological relationships of the earliest South American Paleogene mammalian faunas. Palaeontology 52, 251–269.View article

Gelfo, J.N. & Picasso, M.B.J. 2003. Consideraciones sobre la morfología de astrágalos eutéricos del Eoceno de Patagonia, Argentina. Ameghiniana 40 (4 Sup.), 57.

Gingerich, P.D. 1977. Correlation of tooth size and body size in living hominoid primates, with a note on the relative brain size in Aegyptopithecus and Proconsul. American Journal of Physical Anthropology 47, 395–398.View article

Gingerich, P.D., Smith, B.H. & Rosenberg, K. 1982. Allometric scaling in the dentition of primates and prediction of body weight from tooth size in fossils. American Journal of Physical Anthropology 58, 81–100.View article

Kay, R.F. 1975. The functional adaptations of primate molar teeth. American Journal of Physical Anthropology 43, 195–216.View article

Kramarz, A.G., Bond, M., Gelfo, J.N., López, G., Reguero, M. & Lorente, M. 2011. Critical examination of the supposed afrotherian-like delayed dental eruption in Astrapotheres, Pyrotheres and Xenungulates. Congreso Latinamericano de Paleontología de Vertebrados, San Juan.

López, G.M., Gelfo, J.N., Bond, M., Lorente, M. & Reguero, M. in press. Towards the origin of South American native ungulates and their diversity in Paleocene and Eocene setting. In Rosemberger, A.L.&Tejedor, M.F. (eds) Origins and evolution of Cenozoic South American mammals. Springer.

Lorente, M., Gelfo, J.N., Bond, M., López, G.M., Kramarz, A. & Reguero, M. 2011. The Cotylar Fossa is not a common synapomorphy to link Afrotherian mammals and South American native ungulates. IV Congreso Latinamericano de Paleontología de Vertebrados, San Juan.

McKenna, M.C. 1975. Toward a phylogenetic classification of the Mammali, 21–46a. In Luckett, W.P. & Szalay, F.S. (eds) Phylogeny of the Primates. Plenum Press, New York.

McKenna, M.C. & Bell, S.K. 1997. The Classification of Mammals. Above species level. 640 pp. Columbia University Press.

MacPhee, R.D.E. 1994. Morphology, adaptations, and relationships of Plesiorycteropus, and a diagnosis of a new order of eutherian mammals. Bulletin of the American Museum of Natural History 220, 1–214.

Muizon, C. De & Cifelli, R.L. 2000. The “Condylarths” (archaic Ungulata, Mammalia) from early Palaeocene of Tiupampa (Bolivia): implications on the origin of the South American ungulates. Geodiversitas 22(1), 47–150.

Murphy, W.J., Eizirik, E., Johnson, W.E., Zhang, P., Ryder, O.A. & O’Brien, S.J. 2001. Molecular phylogenetics and the origins of placental mammals. Nature 409, 614–618.View article

Packard, G.C. & Boardman, T.J. 2008. Model selection and logarithmic transformation in allometric analysis. Physiological and Biochemical Zoology 81(4), 496–507.View article

Pascual, R. 1996. Late Cretaceous – Recent landmammals. An approach to South American geobiotic evolution. Mastozoología Neotropical 3, 133–152.

Pascual, R. & Ortíz Jaureguizar, E. 2007. The Gondwanan and South American episodes: two major and unrelated moments in the history of the South American mammals. Journal of Mammalian Evolution 14(2), 75–137.View article

Salton, J.A. & Szalay, F.S. 2004. The tarsal complex of Afro-Malagasy Tenrecoidea: a search for phylogenetically meaningful characters. Journal of Mammalian Evolution 11, 73–104.View article

Sánchez-Villagra, M.R., Narita, Y. & Kuratani, S. 2007. Thoracolumbar vertebral number: the first skeletal synapomorphy for afrotherian mammals. Systematic and Biodiversity 5(1), 1–7.View article

Scott, W.B. 1910. Litopterna of the Santa Cruz beds. Reports of the Princeton University Expedition to Patagonia 1896–1899 7(1), 1–156.

Shockey, B.J. & Flynn, J.J. 2007. Morphological diversity in the postcranial skeleton of Casamayoran (?Middle to Late Eocene) Notoungulata and foot posture in notoungulates. American Museum Novitates 3601, 1–26.View article

Simpson, G.G. 1948. The beginning of the Age of the Mammals in South America. Part I. Bulletin of the American Museum of Natural History 91, 1–232.

Simpson, G.G. 1980. Splendid isolation. The curious history of South American mammals. 275 pp. Yale University Press, New Haven.

Soria, M.F. 2001. Los Proterotheriidae (Litopterna, Mammalia), sistemática, origen y filogenia. Monografías del Museo Argentino de Ciencias Naturales 1, 1–167.

Springer, M.S., Murphy, W.J., Eizirik, E., Madsen, O., Scally, M., Douady, C.J., Teeling, E., Sanhope, M., De Jong, W.W.& O’Brien, S.J. 2007. A molecular classification for the living orders of placental mammals and the phylogenetic placement of primates, 1–17. In Ravosa, M.J. & Dagosto, M. (eds) Primate Origins: Adaptations and Evolution. Springer, New York.

Tabuce, R., Marivaux, L., Adaci, M., Bensalah, M., Hartengerger, J.L., Mahnboubi, M., Mébrouk, F., Tafforeau, P. & Jaeger, J.J. 2007. Early tertiary mammals from North Africa reinforce the molecular Afrotheria clade. Proceedings of the Royal Society of London 274, 1159–1166.View article

Van Valkenburgh, J. 1990. Skeletal and dental predictors of body mass in carnivores, 181–205. In Damuth, J. & MacFadden, B.J. (eds) Body size in mammalian paleobiology. Cambridge University Press.

Waddell, P.J., Kishino, H. & Ota, R. 2001. A phylogenetic foundation for comparative mammalian genomics. Genome Inform Ser Workshop Genome Inform 12, 141–154.

Williamson, T.E. & Carr, T.D. 2007. Bomburia and Ellipsodon (Mammalia, Mioclaenidae) from the early Paleocene of New Mexico. Journal of Paleontology 81, 966–985.View article

Wyss, A.R., Flynn, J.J., Norell, M.A., Swisher, C.C.III, Novacek, M.J., McKenna, M.C. & Charrier, R. 1994. Paleogene mammals from the Andes of Central Chile: A preliminary taxonomic, biostratigraphic, and geochronologic assessment. American Museum Novitates 3098, 1–31.

Zack, S.P., Penkrot, T.A., Bloch, J.I. & Rose, K.D. 2005. Affinities of ‘hyopsodontids’ to elephant shrews and a Holartic origin of Afrotheria. Nature 434, 497–501.View article