Caenolestes

Ladevèze, Sandrine, 2007, Petrosal bones of metatherian mammals from the Late Palaeocene of Itaboraí (Brazil), and a cladistic analysis of petrosal features in metatherians, Zoological Journal of the Linnean Society 150 (1), pp. 85-115 : 107

CAENOLESTES PLUS AUSTRALIDELPHIA

Caenolestes shares with the Australian taxa and Dromiciops four unambiguous synapomorphies. This clade may define the Australidelphia s.l. (see Ladevèze, 2004), and is supported by a raised, anterolaterally directed rostral tympanic process (17 0> 1, RI = 0.778, convergent with didelphids), the development of the caudal tympanic process that floors an epitympanic sinus (26 0> 1, RI = 0.750). These taxa have a tiny to absent petrosal crest (29 0> 1, RI = 0.750), which may represent either a reversal or a secondary acquisition of this feature.