Journal of Mammalian Evolution

, Volume 18, Issue 3, pp 153–161 | Cite as

Protungulatum, Confirmed Cretaceous Occurrence of an Otherwise Paleocene Eutherian (Placental?) Mammal

  • J. David ArchibaldEmail author
  • Yue Zhang
  • Tony Harper
  • Richard L. Cifelli
Original Paper


Neither pre-Cenozoic crown eutherian mammals (placentals) nor archaic ungulates (“condylarths”) are known with certainty based on the fossil record. Herein we report a new species of the Paleocene archaic ungulate (“condylarth”) Protungulatum from undisputed Late Cretaceous aged rocks in Montana USA based on an isolated last upper premolar, indicating rare representatives of these common early Tertiary mammals appeared in North America a minimum of 300 k  years before the extinction of non-avian dinosaurs. The other 1200 mammal specimens from the locality are characteristic Late Cretaceous taxa. This discovery overturns the current hypothesis that archaic ungulates did not appear in North America until after the Cretaceous/Tertiary (K/T) boundary and also suggests that other reports of North American Late Cretaceous archaic ungulates may be correct. Recent studies, including ours, cannot determine whether Protungulatum does or does not belong to the crown clade Placentalia.


Eutheria Placentalia Archaic ungulate Protungulatum Late Cretaceous Hell Creek Formation 



We thank an anonymous reviewer, A. O. Averianov, W. A. Clemens, J. P. Hunter, and G. P. Wilson, for comments that improved the manuscript. W. A. Clemens and P. Holroyd are thanked for specimen loans from the UCMP, Marshal Hedin for photographic help, and Tod Reeder for systematic help to Tony Harper.


  1. Archibald JD (1982) A study of Mammalia and geology across the Cretaceous-Tertiary boundary in Garfield County, Montana. Univ Calif Publ Geol Sci 122:1–286Google Scholar
  2. Archibald JD (1998) Archaic ungulates (“Condylartha”). In: Janis CM, Scott KM, Jacobs LL (eds) Evolution of Tertiary Mammals of North America. Vol. 1, Terrestrial Carnivores, Ungulates, and Ungulatelike Mammals. Cambridge University Press, Cambridge, pp 292–331Google Scholar
  3. Archibald JD (2011) Extinction and Radiation: How the Fall of the Dinosaurs Led to the Rise of Mammals. Johns Hopkins University Press, BaltimoreGoogle Scholar
  4. Belt EB, Hicks JF, Murphy DA (1997) A pre-Lancian regional unconformity and its relationship to Hell Creek paleogeography in south-eastern Montana. Contrib Geol Univ Wyo 31:1–26Google Scholar
  5. Cifelli RL, Eberle JJ, Lofgren DL, Lillegraven JA, Clemens WA (2004) Mammalian biochronology of the latest Cretaceous. In: Woodburne MO (ed) Late Cretaceous and Cenozoic Mammals of North America. Columbia University Press, New York, pp 21–42Google Scholar
  6. Clemens WA (1973) Fossil mammals of the type Lance Formation Wyoming, Part III. Eutheria and summary. Univ Calif Publ Geol Sci 94:1–102Google Scholar
  7. Clemens WA (2002) Evolution of the mammalian fauna across the Cretaceous Tertiary boundary in northeastern Montana and other areas of the Western Interior. Geol Soc Am Spec Pap 361:217–245Google Scholar
  8. Clemens WA (2010) Were immigrants a significant part of the earliest Paleocene mammalian fauna of the North American Western Interior? Vertebr PalAsiatic 48:285–307Google Scholar
  9. Fox RC (1989) The Wounded Knee local fauna and mammalian evolution near the K/T boundary, Saskatchewan, Canada. Palaeontographica Abt A 208:11–59Google Scholar
  10. Fox RC, Naylor BG (2003) A Late Cretaceous taeniodont (Eutheria, Mammalia) from Alberta, Canada. N Jb Geol Paläont Abh 229:393–420Google Scholar
  11. Gradstein F, Ogg J, Smith A (eds) (2004) A Geologic Time Scale. Cambridge University Press, CambridgeGoogle Scholar
  12. Hicks JF, Johnson KR, Obradovich JD, Tauxe L, Clark D (2002) Magnetostratigraphy and geochronology of the Hell Creek and basal Fort Union formations of southwestern North Dakota and a recalibration of the age of the Cretaceous-Tertiary boundary. Geol Soc Am Spec Pap 361:35–56Google Scholar
  13. Hunter JP, Archibald JD (2002) Mammals from the end of the age of dinosaurs in North Dakota and southeastern Montana, with a reappraisal of geographic differentiation among Lancian mammals. Geol Soc Am Spec Pap 361:191–216Google Scholar
  14. Johnson KR, Hickey LJ (1990) Megafloral change across the Cretaceous/Tertiary boundary in the northern Great Plains and Rocky Mountains, USA. Geol Soc Am Spec Pap 247:433–444Google Scholar
  15. Kass RE, Raftery AE (1995) Bayes factors. J Am Stat Assoc 90:773–795CrossRefGoogle Scholar
  16. Kielan-Jaworowska Z, Cifelli RL, Luo Z-X (2004) Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure. Columbia University Press, New YorkGoogle Scholar
  17. Lewis PO (2001) A likelihood approach to estimating phylogeny from discrete morphological character data. Syst Biol 50:913–925PubMedCrossRefGoogle Scholar
  18. Lofgren DL (1995) The Bug Creek problem and the Cretaceous-Tertiary transition at McGuire Creek, Montana. Univ Calif Publ Geol Sci 140:1–185Google Scholar
  19. Lofgren DL, Lillegraven JA, Clemens WA, Gingerich PD, Williamson TE (2004) Paleocene biochronology: the Puercan through the Clarkforkian land mammal ages. In: Woodburne MO (ed) Late Cretaceous and Cenozoic Mammals of North America. Columbia University Press, New York, pp 43–105Google Scholar
  20. Luo Z-X (1991) Variability of dental morphology and the relationships of the earliest arctocyonid species. J Vertebr Paleontol 11:452–471CrossRefGoogle Scholar
  21. Nessov LA, Archibald JD, Kielan-Jaworowska Z (1998) Ungulate-like mammals from the Late Cretaceous of Uzbekistan and a phylogenetic analysis of Ungulatomorpha. Bull Carnegie Mus Nat Hist 34:40–88Google Scholar
  22. Prieto-Marquez A (2010) Global phylogeny of Hadrosauridae (Dinosauria: Ornithopoda) using parsimony and Bayesian methods. Zool J Linn Soc 159:435–502CrossRefGoogle Scholar
  23. Prothero DR, Manning E, Fischer M (1988) The phylogeny of the ungulates. In: MJ Benton (ed) The Phylogeny and Classification of Tetrapods, Volume 2: Mammals. Syst Assoc Spec 35B:201–234Google Scholar
  24. Rougier GW, Wible JR, Novacek MJ (1998) Implications of Deltatheridium specimens for early marsupial history. Nature 396:459–462PubMedCrossRefGoogle Scholar
  25. Silcox MT, Bloch JI, Sargis EJ, Boyer DM (2005) Euarchonta (Dermoptera, Scandentia, Primates). In: Rose KD, Archibald JD (eds) The Rise of Placental Mammals: Origins and Relationships of the Major Extant Clades. Johns Hopkins University Press, Baltimore, pp 127–144Google Scholar
  26. Sloan RE, Van Valen L (1965) Cretaceous mammals from Montana. Science 148:220–227PubMedCrossRefGoogle Scholar
  27. Sloan RE, Rigby JK Jr, Van Valen LM, Gabriel DL (1986) Gradual dinosaur extinction and simultaneous ungulate radiation in the Hell Creek Formation. Science 234:1173–1175PubMedCrossRefGoogle Scholar
  28. Smit J, Van der Kaars S (1984) Terminal Cretaceous extinctions in the Hell Creek Area, Montana: compatible with catastrophic extinction. Science 223:1177–1179PubMedCrossRefGoogle Scholar
  29. Spaulding M, O’Leary MA, Gatesy J (2009) Relationships of Cetacea (Artiodactyla) among mammals: increased taxon sampling alters interpretations of key fossils and character evolution. PLoS ONE 4:1–14CrossRefGoogle Scholar
  30. Van Valen L (1978) The beginning of the age of mammals. Evol Theory 4:103–121Google Scholar
  31. Weil A, Clemens WA (1998) Aliens in Montana: phylogenetically and biogeographically diverse lineages contributed to an earliest Cenozoic community. Geol Soc Am Absts Prgm 30:69–70Google Scholar
  32. Wible JR, Rougier GW, Novacek MJ, Asher RJ (2007) Cretaceous eutherians and Laurasian origin for placental mammals near the K/T boundary. Nature 447:1003–1006PubMedCrossRefGoogle Scholar
  33. Wible JR, Rougier GW, Novacek MJ, Asher RJ (2009) The eutherian mammal Maelestes gobiensis from the Late Cretaceous of Mongolia and the phylogeny of Cretaceous Eutheria. Bull Am Mus Nat Hist 327:1–123CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • J. David Archibald
    • 1
    Email author
  • Yue Zhang
    • 1
    • 2
  • Tony Harper
    • 1
  • Richard L. Cifelli
    • 3
  1. 1.Department of BiologySan Diego State UniversitySan DiegoUSA
  2. 2.Department of Evolution, Ecology and Organismal BiologyOhio State UniversityColumbusUSA
  3. 3.Oklahoma Museum of Natural HistoryUniversity of OklahomaNormanUSA

Personalised recommendations