The families and genera of living rodents / by J.R. Ellerman ; with a list of named forms (1758-1936) by R.W. Hayman and G.W.C.Holt.

Abstract

Geographical Distribution. -Throughout the Holarctic, Indo-Malayan, Australasian, African and Neotropical regions, from Arctic regions of Eurasia south to the Cape of Good Hope, and Tasmania; east to Fiji and other islands of the Pacific; Madagascar; and in the New World from Arctic regions including Greenland south to Tierra del Fuego, and including the Galapagos Islands. Number of Genera. -I have examined and retained one hundred and eight)'-six genera, divided among twelve subfamilies. At least six, and perhaps more, valid genera are not represented in the British Museum.(In the first volume, containing all other Rodents, one hundred and fortyseven genera were retained, and four besides these are not represented in London.)The Family Muridae belongs according to the present classification to the Superfamily Muroidae, a group containing also four families, Muscardinidae, Lophiomyidae, Rhizomyidae, and Spalacidae, which have been dealt with in the first volume.A key to these families has already been given. Notes on the essential characters of the family Muridae have also been given in Volume I. For reference purposes, these are repeated here.Char.\cters.-Zvgomasseteric structure primitively (Deomys), nearly as in Sicistinae (Dipodidae), except that the infraorbital foramen is more generalized, less enlarged, and not conspicuously wider below than above.In all remaining genera the zygomatic plate is broadened and tilted upwards to a greater or lesser degree; masseter lateralis extends its line of I -Living Rodents -II iWith reftrcnct to the cheekteeth formula of Muridae, I must note that according to some authors, the three cheekteeth represent P.4, M.i, and M.2, and it is suggested that M.3 is suppressed. There seems to be considerable evidence in favour of this view'; but for convenience throughout this work I adopt the customary notation. THE RATS FROM MADAGASCAR I'here are six genera that I have examined, containing seven well-marked species in all, from Madagascar. They are excessively difficult to classify. Most authors have referred them to a subfamily Nesomyinae, whose sole character seems to be "Habitat in Madagascar," or dumped them all in the subfamily Cricetinae. It does not seem to me possible to take either course.The sole character given by Tullberg for the group which is unusual among the Muridae he examined is the fact that the tongue possesses three papillae circumvallatae, but he only examined two genera, .Gymnuromys and Eliitrus. But this character, although in most other Muridae he examined was reduced to one, was present in Cricetomys (three); while two were present in Myospalax and Tachyoryctes. It is not a character which one can use throughout the Order; and is apparently variable in closely allied genera in other groups (for instance, Petaurista, o, Pteromys, 3, in the Pteromys group of Sciuridae). It is probably merely a primitive character which may be met with in any group.The Rats of Madagascar may be arranged as follows, in key form.Skull specialized, Microtine in aspect, with zygo...

Molecular Phylogeny of the Chipmunks Inferred from Mitochondrial Cytochrome b and Cytochrome Oxidase II Gene Sequences

“…Howell (1929) expanded the two-genus model by further dividing Eutamias into two subgenera, Eutamias (T. sibiricus) and Neotamias (western North American species). Ellerman (1940) in his study of rodent genera did not accept Eutamias as a valid genus, because he did not consider the characters used to elevate it to a generic rank to be phylogenetically informative. These characters include the presence/absence of the P3 upper premolar, which Ellerman pointed out were previously shown to have no importance in demonstrating evolutionary relationships.…”

“…These characters include the presence/absence of the P3 upper premolar, which Ellerman pointed out were previously shown to have no importance in demonstrating evolutionary relationships. Ellerman (1940) suggested that color pattern is too influenced by the environment and that geographical distribution is not an acceptable phylogenetic character. Bryant (1945) examined this taxonomic question on the basis of fossil evidence.…”

“…Bryant demonstrated that the primitive dentition includes the upper P3 tooth and concluded that the absence of the upper P3 is merely the final phase of an evolutionary trend and has no supraspecific significance. Bryant concluded that Ellerman's (1940) grouping of all chipmunk species into one genus, Tamias, was correct. White (1953a) evaluated the Tamias species on the basis of bacular morphology, cranial morphology, malleus, hyoid process, dentition, and external features.…”

“…There have been diverse attempts to determine the patterns of evolution, dispersal, and relatedness among these taxa. The different data sets have generated varying conclusions about the systematics of chipmunks, ranging from the currently recognized single genus (Tamias) with three subgenera, to previous designations that included two separate genera with one genus being further subdivided into two subgenera, to the designation of three separate genera (Tamias, Neotamias, and Eutamias) for all chipmunk species (Allen, 1891;Howell, 1929;Ellerman, 1940;White, 1953a;Nadler, 1964;Nadler et al, 1969Nadler et al, , 1977Nadler et al, , 1985Ellis and Maxson, 1979;Hafner, 1984;Levenson et al, 1985;Jameson, 1999). We investigated the taxonomy of this group by generating a molecular phylogeny based on mitochondrial DNA (mtDNA).…”

A review of the rodent fauna of Seram, Moluccas, with the description of a new subspecies of mosaic‐tailed rat, Melomys rufescens paveli

“…Compared to other Rattus, it exhibits an intriguing mosaic of both 'archaic' traits (see Aplin, Chesser & ten Have, 2003) and highly-derived features, the latter including the unique configuration of the palate (Thomas, 1922;Ellerman, 1941). In all known specimens, head and body length measures 118-135 mm (n = 3), tail length 126-140 mm (n = 4), hindfoot length 28-30 mm (n = 4), ear length 17-18 mm (n = 4), and weight 66.5 g (n = 1).…”