Naturwissenschaften

, Volume 99, Issue 6, pp 449–463

Persistence of a Mesozoic, non-therian mammalian lineage (Gondwanatheria) in the mid-Paleogene of Patagonia

  • Francisco J. Goin
  • Marcelo F. Tejedor
  • Laura Chornogubsky
  • Guillermo M. López
  • Javier N. Gelfo
  • Mariano Bond
  • Michael O. Woodburne
  • Yamila Gurovich
  • Marcelo Reguero
Original Paper

DOI: 10.1007/s00114-012-0919-z

Cite this article as:
Goin, F.J., Tejedor, M.F., Chornogubsky, L. et al. Naturwissenschaften (2012) 99: 449. doi:10.1007/s00114-012-0919-z

Abstract

We describe two isolated molariforms recovered from early–middle Eocene (early Lutetian) levels of northwestern Patagonia, Argentina. Comparisons with major lineages of therian and non-therian mammals lead us to refer them to a new genus and species of Gondwanatheria (Allotheria). There is a single root supporting each tooth that is very short, wide, rounded, and covered by cementum; the steep sidewalls, lack of a neck between the crown and root, and the heavily worn stage in both molariforms suggest that they were of a protohypsodont type. Both teeth are strongly worn at their centers, all along their length, with the labial edge less worn than the lingual; they show strong transverse crests that alternate with lingual grooves. The protohypsodont aspect of the teeth, as well as the strong, transverse crests, are suggestive of sudamericid affinities; on the other hand, the thin enamel layer and the occlusal pattern formed by the crests and grooves shows more similarities to molariform teeth of the Ferugliotheriidae. The new taxon adds evidence regarding the (1) extensive radiation of the Gondwanatheria throughout the Southern Hemisphere, (2) persistence of several lineages well after the Cretaceous/Paleogene boundary, and (3) early evolution of hypsodont types among South American herbivorous mammals.

Keywords

Gondwanatheria South America Paleogene Eocene Hypsodonty 

Abbreviations

AH

Andesitas Huancache Formation

EDJ

enamel-dentine junction

IBC

Ignimbrita Barda Colorada Formation

IPM

interprismatic matrix

LIEB-PV

Vertebrate Paleontology Collection, Laboratorio de Investigaciones en Evolución y Biodiversidad, Esquel

m

meters

Ma

Megannum

MACN PV RN

Sección Paleontología Vertebrados, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Buenos Aires, Vertebrate Paleontology, Río Negro Collection

MF

upper molariform

MLP

División Paleontología Vertebrados, Facultad de Ciencias Naturales y Museo de La Plata (UNLP), La Plata

mm

millimeters

OES

outer enamel surface

PLEX

prismless outer enamel

SALMA

South American Land-Mammal Age

SANU

South American native ungulates

TLH

Tufolitas Laguna del Hunco Formation

UNPSJB

Universidad Nacional de la Patagonia “San Juan Bosco”, sede Esquel

µm

microns (micrometers)

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Francisco J. Goin
    • 1
  • Marcelo F. Tejedor
    • 2
  • Laura Chornogubsky
    • 3
  • Guillermo M. López
    • 4
  • Javier N. Gelfo
    • 1
  • Mariano Bond
    • 1
  • Michael O. Woodburne
    • 5
  • Yamila Gurovich
    • 6
  • Marcelo Reguero
    • 1
  1. 1.CONICET and División Paleontología VertebradosMuseo de La PlataLa PlataArgentina
  2. 2.CONICET and Centro Nacional PatagónicoPuerto MadrynArgentina
  3. 3.CONICET and Sección Paleontología VertebradosMuseo Argentino de Ciencias Naturales “Bernardino Rivadavia”Buenos AiresArgentina
  4. 4.División Paleontología VertebradosMuseo de La PlataLa PlataArgentina
  5. 5.Department of Geology, Museum of Northern ArizonaFlagstaffUSA
  6. 6.School of Biological, Earth and Environmental SciencesUniversity of New South WalesSydneyAustralia

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