Lasiorhinus

Abstract: Near-infrared spectroscopy (NIRS) was used to predict the nutritive value of forage species available to the critically endangered northern hairy-nosed wombat (Lasiorhinus krefftii). Nutritive attributes of the forage successfully estimated included total nitrogen concentration, fibre (including neutral detergent fibre, acid detergent fibre and acid lignin), organic matter, water soluble carbohydrates and in vitro dry matter digestibility. The reported results demonstrate the seasonal variability of the forage resource available to L. krefftii in its tropical savanna habitat. Multivariate modelling of the spectra enabled the nutritive value of forage samples to be estimated with coefficients of determination (r 2 ) of 0.770-0.995 and standard errors of the cross-validation of 0.070-2.850 using a modified partial least-squares analysis technique. The standard error of the laboratory was 0.02-1.42. This study demonstrates that broad-based NIRS predictive equations can be used to predict the nutritive value of a number of plant types available to a herbivore over time. By using NIRS the analyst can rapidly analyse large numbers of samples with limited reduction of precision, thereby enabling large-scale ecological applications that may have previously been impeded by time and costs. Ra s e gr y ws A.and . F W o .

Abstract: Responses to limited water availability were studied in two species of wombats from mesic (Vombatus ursinus) or xeric (Lasiorhinus latifrons) habitats. Four Vombatus and three Lasiorhinus were fed a low-quality straw-based diet containing 0.6% nitrogen and 68% neutral detergent fibre (dry-matter basis). Restriction to 50% of ad libitum intakes of drinking water reduced dry-matter intakes by 30% but did not alter digestibilities of fibre or nitrogen. Nitrogen balances were negative and similar between species and water intakes. Urea pool size (C-14 urea) increased during water restriction but urea-entry rates and the proportion of urea recycled to the gut were similar between water intakes (78-89%). Tritiated water was given to wombats in single intramuscular or intraperitoneal doses. Times to equilibration of tritium in urinary water were large and variable (45 +/- 36 h). Urinary tritium concentrations often declined erratically after equilibration, and were 14 +/- 14% lower than the tritium concentration in the blood. These irregular kinetics for tritiated water suggest that the water-dilution method requires validation for the wombats. Urinary and faecal water losses were reduced by 60% during water restriction. Water was mainly lost in the faeces, which were drier in Lasiorhinus (41 % dry matter) than in Vombatus (31 %). As blood haematocrit and plasma osmolality were similar between water intakes, extracellular spaces were apparently maintained during water restriction. Glomerular filtration rates (creatinine clearance) were low (12 mL min-1) and similar between water intakes. Therefore, a more concentrated urine was produced by tubular resorption in water-restricted wombats. Lasiorhinus had greater urinary osmolalities and urine: plasma ratios of creatinine, which reflected a greater urine-concentrating ability than Vombatus. Apparent water intakes and the ability to reduce urinary and faecal water losses in the wombats are similar to those of kangaroos. The contrasting abilities of Vombatus and Lasiorhinus to minimise both these water losses are directly related to their separate distributions.

Abstract: The original description of the common wombat was given by Geoffroy in 1803, who in the same year applied two different generic names to this marsupial. This has led to some degree of taxonomic confusion which is still evident in the current application of generic names. Two genera of Recent wombats, Vombatus Geoffroy and Lasiorhinus Gray, are recognized in this paper. Descriptions of them and of their better-defined species are provided. A third genus, Wombatula Iredale & Troughton, is not sustained. Of the fossil wombats of comparable size to Recent species, some are considered to be synonymous with Recent species, others are of uncertain specific designation. All are here regarded as belonging to one or other of the two Recent genera. Trends towards gigantism among fossil wombats are reconsidered because of the author's view that the upper incisors of Sceparnodon ramsayi belong to the family Diprotodontidae and ought to be removed from the giant wombat series, with the largest species of which they have previously been associated.

Abstract: The Mygoora Local Fauna (new name) from Mygoora Lake, central Australia (southern Northern Territory), consists of the fossilised remains of 12 vertebrate species referrable to modern taxa. The assemblage includes eight marsupials (Bellongia lesuew; Dasycercus cristicauda, Dasyurus geo.ffroii, Lagorchestes hirsutus, Lasiorhinus cf. latifrons, Macropus rufus, Macrotis lagotis, and Sarcophilus harrisii), two rodents (Notomys alexis and Ralltts villosissimus), and two reptiles (Varanus sp. and a pythonid, ?Bothrochilus sp.). Lasiorhinus sp. (hairy-nosed wombat) is a first record of the genus in the Northern Territory, while Sarcophilus harrisii (Tasmanian devil) is a first record for central Australia, both records representing extensions of prehistoric ranges for these species. Four species (Bettongia Iesueur, Dasyurus geo.ffroii, Lagorchestes ltirsutus and Macro/us lagotis) became regionally extinct in historical times. The fauna is dominated by fossorial species, or species known to occupy existing burrows, that are typical of the Australian arid biogeographic zone. Articulated skeletal remains were preserved in burrows dug into stabilised aeolian sand, with subsequent deflation resulting in localised concentrations of durable fragments at the present land surface. An optically stimulated luminescence (OSL) date of the host aeolian sand provides a maximum age of between 12.1 +/-0.5 and 9.3+/-0.6 ka for the assemblage. A minimum age could not be determined, but biochronological data suggest that the fauna is possibly of latest Pleistocene or early Holocene age.