Loss of Ancient Diversity of Xenarthrans and the Value of Protecting Extant Armadillos, Sloths and Anteaters

  title={Loss of Ancient Diversity of Xenarthrans and the Value of Protecting Extant Armadillos, Sloths and Anteaters},
  author={Sergio Fabi{\'a}n Vizcaino and M. Susana Bargo},
Abstract Armadillos, sloths and anteaters represent a small fragment of a much more diverse fossil assemblage of xenarthrans that includes bizarre forms such as the armored glyptodonts and the giant ground sloths. We reconstruct extinct xenarthrans as living animals, describing their basic biology, behaviors and ecological roles. In this contribution we provide two examples of the ecological diversity of xenarthrans in the geological past that largely surpass the one we know today. One is the… 

New data on the diversity and chronology of the late Miocene Xenarthra (Mammalia) from Ecuador

ABSTRACT Xenarthra are an endemic and relictual clade of Placentalia that played an important role in the biodiversity during the Cenozoic in today South America. Fossil forms representing close to

Unexpected record of the aquatic sloth Thalassocnus (Mammalia, Xenarthra, Folivora) in the upper Neogene of the Puna (Jujuy, Argentina)

ABSTRACT Xenarthra are, very probably, the most basally branching clade among Placentalia, and the result of the so-called “Splendid Isolation” of South America. Although this is the only endemic

The late Oligocene xenarthran fauna of Quebrada Fiera (Mendoza, Argentina) and its implications for sloth origins and the diversity of Palaeogene cingulates

The late Oligocene mammalian fauna of Quebrada Fiera is one of the most diverse of the Deseadan SALMA (South American Land Mammal Age). We describe its endemic xenarthran assemblage, represented by

Ex Situ Approaches for the Conservation of Genetic Resources in the Superorder Xenarthra.

Xenarthra-a superorder of placental mammals endemic to the Neotropics-is represented by armadillos, anteaters, and sloths. Considering their long history in the Americas, extant xenarthrans represent

The evolution of hyoid apparatus in Xenarthra (Mammalia: Eutheria)

The morphology of the hyoid apparatus in xenarthrans is compared, describing its general morphology and variation in each major clade and scoring these variations as phylogenetic characters, which were submitted to ancestral states reconstructions.

Paleobiological Integration of Santacrucian Sloths (Early Miocene of Patagonia)

  • N. Toledo
  • Environmental Science, Geography
  • 2016
The realized niche of each taxon is reconstructed via integration of three paleoecological attributes: body size, dietary habits and substrate preference and the absence of modern analogues of these heavy-sized arboreal and semiarboreal herbivore diversity is discussed.

First phylogenetic analysis of the Miocene armadillo Vetelia reveals novel affinities with Tolypeutinae

Taking into account the scarce record of fossil Tolypeutinae, this new proposal fills an important temporal gap in the evolutionary history of this linage and provides new information on the diagnostic morphological characters of the Priodontini and TolyPEutini.



On the Evolution of Large Size in Mammalian Herbivores of Cenozoic Faunas of Southern South America

The impact of the mega-mammal extinction on the post-Pleistocene evolution of plant communities has not been studied for South America, but it is clear that it produced an enormous ecological gap in the herbivorous guild.

Eucholoeops Ameghino, 1887 (Xenarthra, Tardigrada, Megalonychidae) from the Santa Cruz Formation, Argentine Patagonia: implications for the systematics of Santacrucian sloths

ABSTRACT New well-preserved remains of the megalonychid sloth Eucholoeops Ameghino, 1887 recovered under strict stratigraphic control from late Early Miocene Santa Cruz Formation (c. 19 to 14 Ma;

The Broken Zig-Zag: Late Cenozoic large mammal and tortoise extinction in South America

The idea that human overhunting was the main cause of the extinction in South America is agreed, but according to this interpretation, the slaughtering of mammals was accomplished in a particular climatic, ecological and biogeographical frame.

Evidence for advanced carnivory in fossil armadillos (Mammalia: Xenarthra: Dasypodidae)

The features suggest that Macroeuphractus occupied an extreme position in the carnivorous-omnivorous feeding behavior of euphractines, and its large size indicates that it could have easily preyed on hare-sized vertebrates.

Revisiting the Intertropical Brazilian Species Hoplophorus euphractus (Cingulata, Glyptodontoidea) and the Phylogenetic Affinities of Hoplophorus

A cladistic analysis of 18 taxa, including 13 glyptodont genera and five cingulate outgroups, scored for 151 cranial, dental, and postcranial characters shows that Hoplophorinae and Hop lophorini are both paraphyletic and hasHoplophorus as the sister group to Panochthus based mostly on synapomorphies of the caudal tube.

Determinants of loss of mammal species during the Late Quaternary ‘megafauna’ extinctions: life history and ecology, but not body size

  • C. Johnson
  • Environmental Science
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 2002
This analysis shows two general features of the selectivity of Late Quaternary mammal extinctions in Australia, Eurasia, the Americas and Madagascar that are consistent with extinctions being due to interaction with human populations.

Exoskeleton and Systematics: A Historical Problem in the Classification of Glyptodonts

It is found that some osteoderm characters used by earlier authors to support ancestor-descendent hypotheses are in fact fully homoplastic autapomorphies, and there is no reason to favor exoskeletal characters in glyptodont systematics.

The teeth of the “toothless”: novelties and key innovations in the evolution of xenarthrans (Mammalia, Xenarthra)

  • S. Vizcaino
  • Environmental Science, Geography
  • 2009
The combination of tooth features that characterize xenarthrans might be seen as the key innovation for the ecologic diversity developed at least since the Oligocene, breaking the mold of the tribosphenic condition that constrained the evolution of the other major clades of mammals.

Influence of Tertiary paleoenvironmental changes on the diversification of South American mammals: a relaxed molecular clock study within xenarthrans

The observed synchronicity between planetary and biological events suggests that global change played a crucial role in shaping the evolutionary history of extant xenarthrans, and these findings open ways to test this hypothesis further in other South American mammalian endemics.

Ecological consequences of Late Quaternary extinctions of megafauna

  • C. Johnson
  • Environmental Science, Geography
    Proceedings of the Royal Society B: Biological Sciences
  • 2009
Understanding the past role of giant herbivores provides fundamental insight into the history, dynamics and conservation of contemporary plant communities.