Journal of Mammalian Evolution

, Volume 20, Issue 1, pp 3–21

The Evolution of the Cenozoic Terrestrial Mammalian Predator Guild in South America: Competition or Replacement?

  • Francisco J. Prevosti
  • Analía Forasiepi
  • Natalia Zimicz
Original Paper

DOI: 10.1007/s10914-011-9175-9

Cite this article as:
Prevosti, F.J., Forasiepi, A. & Zimicz, N. J Mammal Evol (2013) 20: 3. doi:10.1007/s10914-011-9175-9

Abstract

South America was isolated from other continents during most of the Cenozoic, developing a singular mammalian fauna. In contrast to North America, Europe, Asia, and Africa, up to the late Neogene, the carnivore adaptive zone in South America was populated by crocodiles (Sebecidae), large snakes (Madtsoiidae), large birds (Phorusrhacidae), and metatherian mammals (Sparassodonta). Sparassodonta were varied and comprised a wide range of body masses (≈ 2–50 kg) and food habits. Their diversity decreased towards the late Miocene (Huayquerian Stage/Age) and the group became extinct in the “middle” Pliocene (≈ 3 Ma, Chapadmalalan Stage/Age). Several authors have suggested that the cause of this decline and extinction was the ingression of carnivorans to South America (about 6–7 Ma ago), because they competed with the Sparassodonta; although this hypothesis has been criticized in recent years. With the intention of testing the hypothesis of “competitive displacement,” we review the fossil record of South American Sparassodonta and Carnivora, collect data about diversity, estimate size and diet, and determine first and last appearances. The diversity of Sparassodonta is low relative to that of Carnivora throughout the Cenozoic with the early Miocene (Santacrucian Stage/Age) showing the greatest diversity with 11 species. In the late Miocene-middle Pliocene (Huayquerian Stage/Age), the fossil record shows overlap of groups, and the Sparassodonta’s richness curve begins to decline with the first record of Carnivora. Despite this overlap, carnivorans diversity ranged from four or fewer species in the late Miocene-Pliocene to a peak of around 20 species in the early Pleistocene (Ensenadan Stage/Age). Carnivora was initially represented by small-sized, omnivorous species, with large omnivores first appearing in the Chapadmalalan Stage/Age. Over this period, Sparassodonta was represented by large and small hypercarnivores and a single large omnivorous species. From this review of the fossil record, it is suggested that factors other than competitive displacement may have caused the extinction of the Sparassodonta.

Keywords

SparassodontaCarnivoraCompetitive displacementEcological replacement

Supplementary material

10914_2011_9175_MOESM1_ESM.xls (51 kb)
ESM 1(XLS 51 kb)
10914_2011_9175_MOESM2_ESM.doc (68 kb)
ESM 2(DOC 68 kb)

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Francisco J. Prevosti
    • 1
  • Analía Forasiepi
    • 2
  • Natalia Zimicz
    • 3
  1. 1.División Mastozoología, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”CONICETBuenos AiresArgentina
  2. 2.Museo de Historia Natural de San RafaelCONICETSan RafaelArgentina
  3. 3.División Paleontología de Vertebrados, Museo de La PlataCONICETLa PlataArgentina