Burramyoidea

Beck, Robin M. D., Voss, Robert S. & Jansa, Sharon A., 2022, Craniodental Morphology And Phylogeny Of Marsupials, Bulletin of the American Museum of Natural History 2022 (457), pp. 1-353 : 235

Burramyoidea + Phalangeroidea

CONTENTS: Burramyidae and Phalangeridae .

STEM AGE: 34.2 Mya (95% HPD: 30.1–38.7 Mya).

CROWN AGE: 29.9 Mya (95% HPD: 25.8–35.4 Mya).

UNAMBIGUOUS CRANIODENTAL SYNAPOMORPHIES: None.

COMMENTS: Our molecular (figs. 27–29) and total-evidence (figs. 32, 33) analyses agree with most recent molecular studies (e.g., Beck, 2008a; Meredith et al., 2008b, 2009a, 2009 c, 2011; Phillips and Pratt, 2008; Mitchell et al., 2014; May-Collado et al., 2015; Duchêne et al., 2018; Álvarez-Carretero et al., 2021) in supporting a clade comprising Phalangeridae (the only extant phalangeroid family) and Burramyidae (the only burramyoid family described to date). However, we found no unambiguous craniodental synapomorphies that support this clade. Two craniodental features optimize as synapomorphies of this clade under Accelerated Transformation only—masseteric fossa imperforate (char. 99: 1→0; ci = 0.333) and first lower premolar present (char. 153: 1→0; ci = 0.500)— although both of these traits appear to be reversals. A third trait optimizes as a synapomorphy under Delayed Transformation—posterior limb of ectotympanic seamlessly fused with pars canalicularis of the petrosal and/or posttympanic process of the squamosal char. 60: 1→2; ci = 0.333).

Aplin and Archer’s (1987) concept of Phalangeroidea included Phalangeridae together with two fossil families, † Ektopodontidae and † Miralinidae , that have not been included here due to a lack of well-preserved cranial material. The earliest fossil records of burraymids and phalangeroids are from the late Oligocene of Australia ( Archer et al., 1999; Long et al., 2002; Archer and Hand, 2006; Black et al., 2012b), which is broadly congruent with our late Eocene to Oligocene estimate for the divergences among these taxa.