Allqokirus australis (Sparassodonta, Metatheria) from the early Palaeocene of Tiupampa (Bolivia) and the rise of the metatherian carnivorous radiation in South America

摘要: The present paper describes a disarticulated skull of Allqokirus australisMarshall & Muizon, 1988, basal sparassodont (Metatheria, Mammalia) from the early Palaeocene (c. 65 Ma.) Tiupampa (Bolivia). specimen includes rostrum and palate with right premaxilla, both maxillae, left lacrimal, palatines most upper teeth. second largest element frontals, squamosal, parietals, supraoccipital, basisphenoid, presphenoid, alisphenoid, part pterygoids. nasals, basioccipital exoccipitals are missing. Other elements petrosal, jugal dentaries. allow for good reconstruction skull, which is thoroughly described compared to that other sparassodonts pucadelphyids, Pucadelphys Andinodelphys. dental morphology australis extremely similar Patene simpsoni Eocene Itaborai (Brazil) presents distinct (although incipient) carnivorous adaptations. Furthermore, some characters ear region (e.g. medial process deep groove internal carotid artery at ventral apex petrosal) also in pucadelphyids same locality. A parsimony analysis performed on basis data matrix 364 38 taxa placed clade (the Mayulestidae) included Mayulestes Patene. This family constitutes sister group all sparassodonts. Our retrieved large composed formally named Pucadelphyda n. superord. superorder represents metatherian radiation Tertiary South America, first known Tiupampa, started diversify probably slightly earlier, during late Cretacous America. So far, no representative has been discovered North At metatherians fauna they fill predaceous mammalian ecological niche. They earliest representatives Sparassodonta, successful persisted America until Pliocene, i.e., more than 63 Ma.