Craniodental Morphology And Phylogeny Of Marsupials Author Beck, Robin M. D. School of Science, Engineering and Environment University of Salford, U. K. & School of Biological, Earth & Environmental Sciences University of New South Wales, Australia & Division of Vertebrate Zoology (Mammalogy) American Museum of Natural History Author Voss, Robert S. Division of Vertebrate Zoology (Mammalogy) American Museum of Natural History Author Jansa, Sharon A. Bell Museum and Department of Ecology, Evolution, and Behavior University of Minnesota text Bulletin of the American Museum of Natural History 2022 2022-06-28 2022 457 1 353 https://bioone.org/journals/bulletin-of-the-american-museum-of-natural-history/volume-457/issue-1/0003-0090.457.1.1/Craniodental-Morphology-and-Phylogeny-of-Marsupials/10.1206/0003-0090.457.1.1.full journal article 10.1206/0003-0090.457.1.1 0003-0090 6971356 † Stilotherium SPECIES SCORED: † Stilotherium dissimile ( type species). GEOLOGICAL PROVENANCE OF SCORED SPECIMENS : Santa Cruz Formation, Santa Cruz Province , Argentina . AGE OF SCORED SPECIMENS: The Santa Cruz Formation contains the type fauna of the Santacrucian SALMA , which is estimated to span about 16–18 Mya in the Atlantic coastal plain and about 14–19 Mya in the Andean foothills based on tephrochronology (Perkins et al., 2012). ASSIGNED AGE RANGE : 19.000 –14.000 Mya. REMARKS: † Stilotherium dissimile is represented by abundant dental specimens from the Santa Cruz Formation, which we used to score this taxon. Unfortunately, well-preserved cranial material is as yet unknown. Specimens of † S. dissimile (including some material originally referred to “ Garzonia ” and “ Halmarhipus ”; see Marshall, 1980; Abello, 2007) have played a key role in discussions regarding antemolar homologies in paucituberculatans (e.g., Sinclair, 1906: 417; Osgood, 1921: 112–116; Ride, 1962; Marshall, 1980: 113–114; Abello, 2007, 2013). † Stilotherium is currently classified as a member of the extant paucituberculatan family Caenolestidae , within the superfamily Caenolestoidea (e.g., Abello, 2007, 2013; Goin et al., 2009a: table 3; Rincón et al., 2015; Abello et al., 2020: fig. 2), and published phylogenetic analyses consistently support a close relationship between † Stilotherium (and another fossil taxon, † Pliolestes ) and extant caenolestids (Goin et al., 2007, 2009a; Abello, 2013; Forasiepi et al., 2013; Rincón et al., 2015; Engelman et al., 2016; Abello et al., 2020).