Isoodon fusciventer Gray 1841

Travouillon, Kenny J. & Phillips, Matthew J., 2018, Total evidence analysis of the phylogenetic relationships of bandicoots and bilbies (Marsupialia: Peramelemorphia): reassessment of two species and description of a new species, Zootaxa 4378 (2), pp. 224-256 : 235

Isoodon fusciventer Gray 1841 new stat.

Isoodon obesulus fusciventer Gray 1841

Holotype. BMNH 41.1176, skin and skull.

Type locality. King George Sound, Western Australia, Australia

Distribution. South-west Western Australia.

Remarks. The results of our analysis show that the current subspecies of Isoodon obesulus do not form a monophyletic clade. This was also recovered in the analysis of Westerman et al. (2012), where Isoodon obesulus fusciventer does not form a clade with Isoodon obesulus obesulus suggesting that it is a distinct taxon. As a result, we propose to raise Isoodon obesulus fusciventer to species status, and provide a new diagnosis.

Diagnosis. Isoodon fusciventer differs from all other Isoodon species in having a large StA on M1, with a long crest running anteroposteriorly (this cusp and crest are small and short in all other taxa). Isoodon fusciventer differs form I. obesulus and I. auratus in having a well-developed lingual shelf that extends to the buccal side on P3; no stylar crest on M1; retaining a StC/D on M4. Isoodon fusciventer differs from I. obesulus and I. macrourus in having fused StB and StC on M1 (these cusps are identifiable as distinct cusps in other taxa); posthypocristid is oblique to the tooth row on m1and m2; preentocristid on m4 is absent. Isoodon fusciventer differs from I. auratus in having an enlarged anterior cingulum on M1 which connects to the talon; having P1 as long as P2 (shorter in I. auratus ). Isoodon fusciventer differs from I. obesulus in having a preparacrista posterobuccally orientated to connect to a posteriorly located StB on M1; having a ventrally angular alisphenoid tympanic process which terminates anterior to the transverse foramen. Isoodon fusciventer differs from I. macrourus in having P2 and P3 subequal in length (P2 is shorter in I. macrourus ); retaining a stylar crest on M2; cristid obliqua on m1 terminates lingual to the protocone but buccal to the midpoint of the tooth width (buccal to the protocone in I. macrourus ).