Uromys Peters, 1867

Groves, C. P. & Flannery, Tim F., 1994, A revision of the genus Uromys Peters, 1867 (Muridae: Mammalia) with descriptions of two new species, Records of the Australian Museum 46 (2), pp. 145-169 : 147-148

Uromys Peters, 1867

Type species. Hapalotis caudimaculatus Krefft, 1867 .

Revised generic diagnosis. The species of Uromys can be differentiated from all other murids in possessing the following combination of features: i) soft palate has between six and 12 irregular ridges in region between molar rows ( Fig. 2 ); ii) palate extends posteriorly beyond posterior margin of M3; iii) lower incisors much deeper than wide; iv) anterolateral spine of bulla greatly expanded.

Notes. McAllen & Bruce (1989) suggest that Melanomys is a new generic name proposed by Winter (1983) for the species hadrourus . This name results from a typographical error in a reference, and in any case is preoccupied by Melanomys Thomas, 1902 .

The generic diagnosis differentiates Uromys from all other Muridae , including its close relatives Solomys and Melomys , with which it agrees in possessing a so-called mosaic tail (described, for example in Tate, 1951). Species of Uromys differ additionally from species of Melomys in their larger size, and from species of Solomys in lacking the latter's greatly thickened palate, and by the relatively larger, thicker incisors, more elongate basoccipital, and the posteriorly broadened palate. We transfer to Uromys two species previously referred to Melomys ( M porculus and M hadrourus ), and transfer salamonis, previously placed within Uromys , to Solomys .

The Discriminant Analysis ( Fig. 3 ) discriminated the quasi-specific samples on the basis of (first function, accounting for 42.5% of total variance) greatest skull length and snout length, and (second function, 35.9% of variance) overall size except for braincase breadth. A third function accounted for 12.3% of variance, but was an absolute size discriminator, distinguishing only U. hadrourus effectively. The two subgenera are not sharply distinguished by the analysis: U. caudimaculatus , U. hadrourus and U. anak are arrayed around one end of a linear clinal spread from U. rex via U. porculus to U. imperator . The result is difficult to interpret, but is consistent with our conclusions (below) that U. rex is the most autapomorphic species in U. ( Cyromys ) and that U. anak is less like other species of U. ( Uromys ) than is U. neobritannicus .

Figures

Fig. 2. The soft palate of (A) Uromys caudimaculatus, (B) U. anak, (C) U. rex, (D) Xenuromys barbatus and (E) Solomys sapientis.

Fig. 3. Discriminant analysis of Uromys. Function 1 (abscissa) accounts for 42.5% of the total variance, and is most highly correlated with greatest skull length and snout length; Function 2 (accounting for 35.9% of total variance) is positively correlated with all variables except braincase width. 1 = U. rex, 2 U. imperator, 3 = U. hadrourus, 4 = U. anak, 5 = U. caudimaculatus, 6 = U. porcu/us, 7 = U. neobritannicus.