Protemnodon devisi, Bartholomai, 1973

Kerr, Isaac A. R., Camens, Aaron B., Van Zoelen, Jacob D., Worthy, Trevor H. & Prideaux, Gavin J., 2024, Systematics and palaeobiology of kangaroos of the late Cenozoic genus Protemnodon (Marsupialia, Macropodidae), Megataxa 11 (1), pp. 1-261 : 193

Protemnodon devisi

Protemnodon devisi Bartholomai, 1973 : Mem. Qld. Mus. 16(3), p. 354— nomen dubium.

Protemnodon devisi was described by Bartholomai (1973) as being distinguishable from P. otibandus ‘… by its smaller permanent premolars and generally larger molars. The trigonid basin in lower molars is broader in P. devisi while the [pre]cingulum in upper molars also appears broader. The upper molars are less ovate in occlusal view, and usually have a moderately well-defined lingual swelling at the margin of the [interloph] valley. The distinct cuspid at the [buccal] end of the [interlophid valley] in m1, regarded by Plane (1967) as diagnostic in P. otibandus , is not developed in any specimen of P. devisi ’ (p. 359).

The holotype of P. devisi (QM F4710, a partial L dentary) preserves only p3 and partial m2–4 with a high level of wear, preventing some molar comparisons with P. otibandus .As is the case with P. chinchillaensis , reference to the variation seen within the better-sampled species P. anak shows that the predicted range of premolar length relative to molar length for a larger sample of P. otibandus would include the sampled range of P. devisi ( Fig. 121 ). The relative width of the trigonid basin is quite variable in the molars of species of Protemnodon , possibly because it is affected by the angle and development of both the premetacristid and the paracristid, as well as the width of the lophid itself, but the feature is certainly too worn in the holotype of P. devisi to be diagnostic in any case. The presence of the cuspid on the buccal margin of the m1 interlophid valley in P. otibandus is variable and not diagnostic (see absence in the unworn m1 of UCMP 45246, paratype). Regardless, the m1 is not preserved in the holotype of P. devisi and so the condition of its talonid basin is not known. As these differences constitute the whole of the specific diagnosis with respect to features of the dentary, there are no grounds for placing the holotype outside of P. otibandus . There is good evidence for a generally larger (though size is not of diagnostic use) species of Protemnodon in Pliocene Australian deposits ( P. dawsonae sp. nov.). This species is supported by characters of the upper molars and i1, which are not preserved in the holotype of P. devisi .As the holotype of P. devisi cannot be unambiguously associated with either P. otibandus or P. dawsonae sp. nov., P. devisi is considered a nomen dubium rather than a junior synonym.

Figures

FIGURE 121. boxplot of p3 length divided by m3 length in specimens of P. anak, P. mamkurra sp. nov., P. viator sp. nov., P. dawsonae sp. nov., P. snewini, P. otibandus, P. tumbuna, and four extrageneric taxa.