A Nearly Complete Juvenile Skull of the Marsupial Sparassocynus derivatus from the Pliocene of Argentina, the Affinities of “Sparassocynids”, and the Diversification of Opossums (Marsupialia; Didelphimorphia; Didelphidae)

  title={A Nearly Complete Juvenile Skull of the Marsupial Sparassocynus derivatus from the Pliocene of Argentina, the Affinities of “Sparassocynids”, and the Diversification of Opossums (Marsupialia; Didelphimorphia; Didelphidae)},
  author={Robin M. D. Beck and Mat{\'i}as L. Taglioretti},
  journal={Journal of Mammalian Evolution},
  pages={385 - 417}
“Sparassocynids” are small, carnivorously-adapted marsupials known from the late Miocene and Pliocene of South America, thought to be relatives of living didelphid opossums but of otherwise uncertain phylogenetic relationships. Here, we describe a nearly complete juvenile skull of the “sparassocynid” Sparassocynus derivatus, from the Pliocene (~5–3 million years old) Chapadmalal Formation, Argentina. It provides new information on the morphology of Sparassocynus, including the deciduous… 

The Stapes of Stem and Extinct Marsupialia: Implications for the Ancestral Condition

ABSTRACT This paper describes, for the first time, the stapedes of several non-marsupial species of the metatherian clade Sparassodonta (Sipalocyon gracilis, Arctodictis sinclairi, and Borhyaena

Phylogenetic affinities and morphology of the Pliocene cathartiform Dryornis pampeanus Moreno & Mercerat

The fossil bird Dryornis pampeanus Moreno & Mercerat, is reinterpreted after examination of new referred material from the Pliocene Chapadmalal Formation of Argentina, and is emended in the light of important considerations that cast doubt on the previous attribution of the taxon to condors.

Amazonia as the Origin and Diversification Area of Didelphidae (Mammalia: Metatheria), and a Review of the Fossil Record of the Clade

The results indicate the relevance of Amazonia in the early diversification of Didelphidae, including the divergence of the major clades traditionally ranked as subfamilies and tribes, and stress that the early history of didelphids is obscured by the lack of Paleogene fossils, which are still to be unearthed from low-latitude deposits of South America.

Upper Oligocene–lower-Middle Miocene peramelemorphians from the Etadunna, Namba and Wipajiri formations of South Australia

Abstract The oldest fossils referable to the marsupial order Peramelemorphia (which includes modern bandicoots and bilbies) stratigraphically date from the upper Oligocene of Australia. Here we

Variability and variation in Rhyncholestes raphanurus Osgood (Paucituberculata, Caenolestidae)

Comparative studies of continental and Chiloé Island specimens support the treatment of R. raphanurus as a single valid species, especially since morphologic and morphometric differences fall within the extremes of continental populations.

Strangers in a strange land: Ecological dissimilarity to metatherian carnivores may partly explain early colonization of South America by Cyonasua-group procyonids

Abstract. It was once thought that the endemic carnivorous mammals of South America, the metatherian sparassodonts, were driven extinct by North American carnivorans through competitive exclusion.

The multicausal twilight of South American native mammalian predators (Metatheria, Sparassodonta)

Sparassodonts were the apex mammalian predators of South America throughout most of the Cenozoic, diversifying into a wide array of niches including fox-like and even saber-toothed forms. Their

Craniodental Morphology and Phylogeny of Marsupials

The results of separate and combined analyses of these data using a wide range of phylogenetic methods support many currently accepted hypotheses of ingroup (marsupial) relationships, but they also underscore the difficulty of placing fossils with key missing data.

An Annotated Checklist of Recent Opossums (Mammalia: Didelphidae)

  • R. Voss
  • Biology
    Bulletin of the American Museum of Natural History
  • 2022



Description of a new species of Sparassocynus (Marsupialia: Didelphoidea: Sparassocynidae) from the late Miocene of Jujuy (Argentina) and taxonomic review of Sparassocynus heterotopicus from the Pliocene of Bolivia.

A new species of sparassocynid marsupial from the late Miocene of Maimará Formation (Jujuy Province, Argentina) is described from a left mandibular fragment with a complete p2-m4 series, adding new information to evaluate the origins and early diversification of sparASSocynids.

A New Species of Small-Bodied Sparassodont (Mammalia, Metatheria) from the Middle Miocene Locality of Quebrada Honda, Bolivia

This specimen suggests that the appearance of the Sparassocynidae and several hypercarnivorous didelphid taxa (including Thylophorops, Thylatheridium, Lutreolina, and Hyperdidelphys) represent an evolutionary response to the decline in small, predatory sparassodont taxa during the late Cenozoic.

Sparassocynus (Marsupialia, Didelphidae), a peculiar mammal from the late Cenozoic of Argentina

The extinct genus Sparassocynus is known from the Montehermosan, Chapadmalalan, and Uquian stages of Argentina, spanning the Pliocene-Pleistocene transition, and a relative occurs in the older

The Osteology and Systematics of the Enigmatic Australian Oligo-Miocene Metatherian Yalkaparidon (Yalkaparidontidae; Yalkaparidontia; ?Australidelphia; Marsupialia)

It is concluded that the ordinal status of Yalkaparidon remains justified based on current evidence, and the two currently recognized species, Y. coheni and Y. jonesi, are maintained, and a revised diagnosis for YalkAParidontia is presented.

Two new late Tertiary marsupials (Hathlyacyninae and Sparassocyninae) from the Bolivian Altiplano

Two new species of fossil Marsupialia are described from beds of late Tertiary age on the Altiplano south of La Paz, Bolivia. Borhyaenidium altiplanicus n. sp. (Borhyaenidae, Hathlyacyninae) is

Contribution to the Knowledge of the Sparassocynidae (Mammalia, Metatheria, Didelphoidea), with Comments on the Age of the Aisol Formation (Neogene), Mendoza Province, Argentina

The discovery of new specimens suggests that the stratigraphic level where the marsupial was found may have been deposited during the late Miocene (not older than Huayquerian times), which would mean that the sparassocynid clade has a long ghost lineage that covers at least 10 million years.

Notes on Didelphidae (Mammalia, Marsupialia) from the Huayquerian (Pliocene) of Argentina. American Museum novitates ; no. 2559

It is concluded that sampling of small fossil mamals is inadequate in South America but also that much, perhaps most, of didelphid evolution was occurring outside the regions of known fossil fields.

New palaeothentid marsupials (Paucituberculata) from the middle Miocene of Quebrada Honda, Bolivia, and their implications for the palaeoecology, decline and extinction of the Palaeothentoidea

Paucituberculatan marsupials, particularly members of the family Palaeothentidae, were important components of South American mammal communities during much of the Cenozoic. However, after the late

A New Marsupial from the Early Eocene Tingamarra Local Fauna of Murgon, Southeastern Queensland: A Prototypical Australian Marsupial?

Djarthia murgonensis, a new genus and species of marsupial from the early Eocene Tingamarra Local Fauna of Murgon in southeastern Queensland, is described on the basis of dental material and suggests phylogenetic placement within either Didelphidae or Australidelphia.