Petauroidea Bonaparte, 1832

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 : 239-240

Petauroidea Bonaparte, 1832

CONTENTS: Acrobatidae , Petauridae , Pseudocheiridae , and Tarsipedidae .

STEM AGE: 33.0 Mya (95% HPD: 29.3–37.7 Mya).

CROWN AGE: 29.0 Mya (95% HPD: 26.4–32.7 Mya).

UNAMBIGUOUS CRANIODENTAL SYNAPOMORPHIES: Maxillary foramen bordered by lacrimal (char. 14: 1→0; ci = 0.200); postorbital process formed by frontal and parietal (char. 19: 1→0; ci = 0.400); scars of M. temporalis origin on braincase not fused middorsally to form sagittal crest in adults (char. 27: 1→0; ci = 0.059); dP3 very small, nonoccluding, and structurally simplified or absent (char. 120: 0→2; ci = 0.118); and third upper premolar (P3) conventionally premolariform (char. 123: 2→0; ci = 0.385).

COMMENTS: The superfamily Petauroidea comprises four morphologically disparate families of phalangeridans: Acrobatidae , Tarsipedidae , Petauridae , and Pseudocheiridae . Nevertheless, petauroid monophyly is strongly supported in our molecular (figs. 27–29) and total-evidence (figs. 32, 33) analyses, as it has also been in other recent molecular studies ( Phillips and Pratt, 2008; Meredith et al., 2009a, 2009 c, 2011; Mitchell et al., 2014; May-Collado et al., 2015; Duchêne et al., 2018; Álvarez-Carretero et al., 2021). One of the five unambiguous craniodental synapomorphies found to support Petauroidea is a reversal, namely reacquisition of a conventionally premolariform morphology of the third upper premolar from a fully sectorial precursor that is inferred as having evolved deeper within Diprotodontia .

The branching order within Petauroidea recovered in both of our total-evidence analyses (figs. 32, 33)—with Petauridae and Pseudocheiridae forming a clade, Tarsipedidae sister to this, and Acrobatidae the first family to diverge—is congruent with the results of recent molecular studies ( Phillips and Pratt, 2008; Meredith et al., 2009a, 2009 c, 2011; Mitchell et al., 2014; May-Collado et al., 2015; Duchêne et al., 2018; Álvarez-Carretero et al., 2021). The oldest described petauroids are pseudocheirids from the late Oligocene of central Australia and Riversleigh World Heritage Area ( Archer et al., 1999; Long et al., 2002; Archer and Hand, 2006; Roberts, 2008; Roberts et al., 2009; Black et al., 2012b), indicating that the petauroid crown clade had already begun to diversify by this time; our estimated divergence times imply that the first split within Petauroidea occurred during the Oligocene.