Phylogeny of the Australian Rodents (Muridae) - a Molecular Approach Using Microcomplement Fixation of Albumin

Abstract

Microcomplement fixation was used to assess albumin evolution in the history of the rodents of Australia. The results confirmed a monophyletic grouping consisting of the genera Pseudomys, Mastacomys and Notomys, and showed that the genus Pseudomys is paraphyletic. The genera Conilurus, Leporillus and Mesembriomys also formed a monophyletic group. A significant finding was that Leggadina was distantly related to all Pseudomys species, and indeed may be the earliest offshoot of all Australian rodents other than Rattus. Albumin evolution in the Australian rodents has occurred in a manner far from clock-like. Mastacomys Thomas, 1882 is synonymised with Pseudomys Gray, 1832.

The impact of fossil calibrations, codon positions and relaxed clocks on the divergence time estimates of the native Australian rodents (Conilurini)

“…Both these genera are represented in the Rackham's Roost assemblage as well as at a second locality in northern Queensland (Chinchilla Local Fauna), indicating that these genera were once widespread (Long et al, 2002). A study of albumin microcomplement fixation identified Leggadina as the sister-group to the remaining Conilurini (Watts et al, 1992). The most recent study, based on protein-coding data supported that Leggadina is the sister-group to a subgroup of Conilurini (Rowe et al, 2008) (Fig.…”

“…Today Australia is home to over 70 species of native rodents (Musser and Carleton, 1993;Strahan, 1995;Tate, 1951;Watts and Aslin, 1981). The Australian rodents are traditionally divided into three groups: Conilurini, Uromyini and Rackham's Roost, Floraville and Chinchilla assemblages in Queensland have yielded a diversity of these first rodent fossils (Long et al, 2002).…”

Biological determinants of extinction risk: why are smaller species less vulnerable?

“…To identify contrasts I constructed a composite species-level phylogeny of Australian mammals from published phylogenies (Watts & Aslin, 1981;Flannery, 1989;Watts et al, 1992;Strahan, 1995;Watts & Baverstock, 1995;Kirsch, Lapointe & Springer, 1997;Krajewski, Buckley & Westerman, 1997;Blacket et al, 1999). This is not an exhaustive list of phylogenetic studies of Australian mammals, but, in choosing studies, I favoured more recent and more comprehensive phylogenies, particularly those which synthesized results from several earlier studies.…”

A new species of murid rodent (genus Mayermys) from south-eastern New Guinea

“…This group, often classified as the murid subfamily Hydromyinae or (now more commonly) the murine tribe Hydromyini (Watts and Baverstock 1994;Flannery 1995) includes the murid genera Hydromys E. Geoffroy, 1804, Parahydromys Poche, 1906, Crossomys Thomas, 1907, Microhydromys Tate and Archbold, 1941, Paraleptomys Tate and Archbold, 1941, Xeromys Thomas, 1889, Leptomys Thomas, 1897, Pseudohydromys Ru È mmler, 1934, Neohydromys Laurie, 1952, and Mayermys Laurie and Hill, 1954(Watts et al 1992Breed 1997; reviewed by Musser and Carleton 2004) (however, both the integrity of this large grouping and the boundaries and interrelationships of certain genera remain to be firmly established; see Musser and Carleton 2004). Of these genera, one of the most phenetically distinctive is Mayermys, diagnosed by possession of only a single molar in each quadrant of the jaw (i. e. with only eight teeth in total ± four incisors and four molars, fewer than any other rodent).…”