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 † Badjcinus SPECIES SCORED: † Badjcinus turnbulli ( type and only described species). GEOLOGICAL PROVENANCE OF SCORED SPECIMENS : White Hunter Site (Riversleigh Faunal Zone A), Riversleigh World Heritage Area, Queensland , Australia . AGE OF SCORED SPECIMENS: Riversleigh Faunal Zone A is currently interpreted to be late Oligocene based on biostratigraphy (Archer et al., 1989, 1994, 1995, 1997, 2006; Creaser, 1997; Myers and Archer, 1997; Travouillon et al., 2006; Black, 2010; Black et al., 2012b, 2013; Woodhead et al., 2014; Arena et al., 2015). Specifically, Myers and Archer (1997) correlated it with the Ngama Local Fauna, which occurs in Zone D of the Etadunna Formation at Mammalon Hill, South Australia , based on the shared presence of the ilariid † Kuterintja ngama . Based on palaeomagnetic data presented by Woodburne et al. (1994), Metzger and Retallack (2010) estimated the Etadunna Formation to span 26.1–23.6 Mya, so a similar age range for Riversleigh Faunal Zone A seems plausible. However, pending the publication of absolute dates, a more conservative approach is to use the entire range of the late Oligocene (Chattian; Cohen et al., 2013 [updated]) for this taxon. ASSIGNED AGE RANGE : 27.820 –23.030 Mya. REMARKS: † Badjcinus turnbulli is the oldest fossil dasyuromorphian represented by relatively wellpreserved craniodental material. It is currently known from a single partial cranium that includes a well-preserved auditory region ( QM F30408 ) and additional dental specimens (Muirhead and Wroe, 1998). † Badjcinus turnbulli differs from all other known dasyuromorphians in lacking both a squamosal epitympanic sinus and a distinct rostral tympanic process of the petrosal, although there is some debate as to whether these features are plesiomorphic or apomorphic (Muirhead and Wroe, 1998; Murray and Megirian, 2006a). Muirhead and Wroe (1998) identified † Badjcinus as a thylacinid, and thylacinid affinities for this taxon have been supported in most phylogenetic analyses (Wroe and Musser, 2001; Murray and Megirian, 2006a; Yates, 2014, 2015b; Archer et al., 2016; Kealy and Beck, 2017; Rovinsky et al., 2019). However, the craniodental analysis of Wroe et al. (2000) placed † Badjcinus closer to Dasyuridae than to Thylacinus , and the dated total evidence analyses of Kealy and Beck (2017) recovered † Badjcinus as sister to all other dasyuromorphians, and hence outside the crown clade (Dasyuroidea sensu Kealy and Beck, 2017: table 1 ). We therefore follow Kealy and Beck (2017) as classifying † Badjcinus as? Thylacinidae .