This thesis examined the hypotheses that the mucus lining of the gastrointestinal tract (GIT) of Australian marsupials is colonised with large populations of spiral and fusiform shaped bacteria, many of which belong to the genus Helicobacter and that these Helicobacter species are likely be unique. The presence of spiral and fusiform shaped bacteria in the GIT of 8 Australian marsupial species (32 animals in total) was examined using microscopy, culture and Helicobacter genus specific PCR. The marsupials studied included the brushtail possum, ringtail possum, koala, wombat, Eastern grey kangaroo, Tasmanian devil, Eastern quoll and long nosed bandicoot. The spiral and fusiform shaped isolates were characterised and identified using morphological appearance, Helicobacter genus specific PCR and 16S rRNA gene sequence comparisons. The spatial distribution of Helicobacter species in the GIT sections was examined microscopically in silver stained sections of the GIT and using Fluorescent in situ hybridisation (FISH) with a Helicobacter genus specific probe. Spiral and/or fusiform shaped bacteria were detected and/or isolated from all marsupials studied. The prevalence and bacterial load of these organisms was found to differ in each marsupial species. These bacteria were found to belong to 3 different genera (Helicobacter, Campylobacter and Desulfovibrio). Each marsupial species appeared to be colonised with one or more unique Helicobacter species. Comparison of the detection of Helicobacter species in different groups of marsupials (herbivores, omnivores and carnivores) suggests that diet as well as the function and structure of the GIT may have a significant impact on their colonisation. Phylogenetic analysis of the new possum Helicobacters showed that they shared a common ancestor. Comparison of Helicobacter species isolated from different species of marsupial and placental mammals, as well as birds, showed that differences in environmental location i.e. gastric vs lower bowel had a major impact on the position of the Helicobacters on the phylogenetic tree.

The fossil record of marsupial lions (family Thylacoleonidae) from Australian Oligo Miocene deposits is generally poor. Study of new material of this family collected from Oligo-Miocene limestone sediments of the Riversleigh World Heritage Area, northwestern Queensland adds significant new information about previously described species and also indicates a greater diversity of thylacoleonids during this period of geological time. Two new genera and five new species are described. Reassessment of the holotype of the type species of Priscileo, P. pitikantensis,indicates it shows stronger affinities to species of the genus Wakaleo than it does to Priscileo roskellyae. Priscileo is regarded here to be a junior synonym of Wakaleo. The cranium and lower dentition of Priscileo roskellyae show significant morphological differences from species of Wakaleo, and this species is referred to a new genus, Lekaneleo. Distinctive morphological differences are identified in the M3s of Wakaleo oldfieldi and W. vanderleueri, species previously distinguished only by relative size differences in their dentitions. Functional morphological assessment of postcranial remains of species of Wakaleo suggests that they were probably scansorial or arboreal, but does not support a previous hypothesis of a fossorial habit. Cladistic analyses of the interrelationships of marsupial lions support the referral of Priscileo pitikantensis to the genus Wakaleo. The monotypic genus Microleo is the sister-group to all remaining thylacoleonid taxa. Species of Lekaneleo are the sistergroup to a Wakaleo/Thylacoleo clade. Intraordinal relationships of thylacoleonids were also investigated. Phylogenetic analyses of the interrelationships of Diprotodontia that included representatives of all extinct vombatiform families as well as extant taxa were conducted employing cranial and dental morphological characters. These analyses provide support for the hypothesis that Thylacoleonidae are members of the suborder Vombatiformes. Two species of Wakaleo (W. oldfieldi and W. vanderleueri) present in Riversleigh deposits are also found at other localities - respectively, the Leaf Locality of central Australia (Kutjamarpu LF) and the Small Hills Locality of northern Australia (Bullock Creek LF) - and suggest age estimations of the relevant Riversleigh sites of early Miocene and late Miocene. The phyletic evolution of Wakaleo suggests that some Riversleigh deposits are probably late Oligocene in age.

This thesis examines the reproductive biology of red-tailed phascogales, an obligate male semelparous dasyurid species, which is part of a captive breeding colony at Alice Springs Desert Park. The red-tailed phascogale belongs to a group of dasyurids that shows an unusual reproductive strategy amongst mammals, one which provides opportunity for understanding means by which individuals maximise their reproductive success and the role of sperm competition. The broad aim was to gain an understanding of the reproductive biology of red-tailed phascogales and explore means by which individuals can affect their reproductive success. Examination of the red-tailed phascogale reproductive biology showed that females mated with multiple males and were capable of storing sperm in their oviducts for at least a five day period. Captive female red-tailed phascogales showed greater plasticity in their breeding season than has been observed in Antechinus, which exhibits the same life history strategy. Females were observed to invest heavily into the production of young, producing almost twice as many ova (15.1 ± 1.9) as young they can raise and 76% of females filling six to eight of the eight available teats in a breeding attempt. A 63% male bias was observed in young attaching to the teats, which could be produced through differential attachment of the sexes to teats at birth. Of the 846 young born in the captive breeding colony, 68% were weaned, with weaning occurring between 90-110 days of age and a 53% female bias observed in young being weaned. By weaning, a litter of young weighed 380% of the mothers mass with male young tending to be heavier than females by weaning. No relationship was observed between maternal weight and either litter sex ratio or sex biased growth of young. A positive relationship between maternal body mass and body mass of offspring at weaning was observed, with the body mass of young at weaning correlated with its body mass at maturity. Multiple paternity was observed in more than half of the litters examined, with heavier males having increased siring success compared to lighter males. Genotyping showed that the effective population size for the captive colony was 1.9x that observed from the group managed studbook. Male reproduction was also not as tightly constrained as in Antechinus, with spermatogenic failure not occurring in captive populations until after mating had occurred, meaning males are not reliant on epididymal stores alone for successful breeding. Scrotal diameter showed a positive relationship with testis and epididymal mass across male life, although this relationship was not evident when analysis was restricted to the time of peak sperm production. Captive males showed the opposite pattern of testosterone fluctuations to that observed in wild animals, with lowest levels occurring during the mating period. Captive animals were able to survive up to five years in captivity, in contrast to the obligate semelparity observed in wild males. Although most captive females can survive to breed in a second year and females are known to breed in a second year in the wild, the reproductive strategy of females appears to be aimed at maximising the returns on their first breeding attempt. In males, the need to maximise the investment into the first breeding season is amplified through the complete absence of opportunity to breed again; either through post-mating mortality in the wild or spermatogenic failure in captivity. The results of this study have implications for captive breeding of red-tailed phascogales, with their reproductive biology; spermatogenic failure, restricted breeding season, teat number limiting the number of young raised, high lactational investment into young, sex biases, the need to maintain genetic diversity and biases in siring success; providing challenges for the maintenance of a captive population. The results of this study also provide comparative information that contributes to understanding the unusual life history strategy of Phascogale and Antechinus, and contributes to the growing body of knowledge about mating strategies in marsupials. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1330358 / Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Sciences, 2008

The fossil record of marsupial lions (family Thylacoleonidae) from Australian Oligo Miocene deposits is generally poor. Study of new material of this family collected from Oligo-Miocene limestone sediments of the Riversleigh World Heritage Area, northwestern Queensland adds significant new information about previously described species and also indicates a greater diversity of thylacoleonids during this period of geological time. Two new genera and five new species are described. Reassessment of the holotype of the type species of Priscileo, P. pitikantensis,indicates it shows stronger affinities to species of the genus Wakaleo than it does to Priscileo roskellyae. Priscileo is regarded here to be a junior synonym of Wakaleo. The cranium and lower dentition of Priscileo roskellyae show significant morphological differences from species of Wakaleo, and this species is referred to a new genus, Lekaneleo. Distinctive morphological differences are identified in the M3s of Wakaleo oldfieldi and W. vanderleueri, species previously distinguished only by relative size differences in their dentitions. Functional morphological assessment of postcranial remains of species of Wakaleo suggests that they were probably scansorial or arboreal, but does not support a previous hypothesis of a fossorial habit. Cladistic analyses of the interrelationships of marsupial lions support the referral of Priscileo pitikantensis to the genus Wakaleo. The monotypic genus Microleo is the sister-group to all remaining thylacoleonid taxa. Species of Lekaneleo are the sistergroup to a Wakaleo/Thylacoleo clade. Intraordinal relationships of thylacoleonids were also investigated. Phylogenetic analyses of the interrelationships of Diprotodontia that included representatives of all extinct vombatiform families as well as extant taxa were conducted employing cranial and dental morphological characters. These analyses provide support for the hypothesis that Thylacoleonidae are members of the suborder Vombatiformes. Two species of Wakaleo (W. oldfieldi and W. vanderleueri) present in Riversleigh deposits are also found at other localities - respectively, the Leaf Locality of central Australia (Kutjamarpu LF) and the Small Hills Locality of northern Australia (Bullock Creek LF) - and suggest age estimations of the relevant Riversleigh sites of early Miocene and late Miocene. The phyletic evolution of Wakaleo suggests that some Riversleigh deposits are probably late Oligocene in age.

Thesis (Ph. D.A)--University of Adelaide, Dept. of Anatomical Sciences, 1998? / Addendum pasted onto front end-paper. Includes bibliographical references (leaves 214-226).

Thesis (Ph.D.)--University of Adelaide, Dept. of Genetics, 1983. / Typescript (photocopy).

Thesis (Ph. D.)--University of New South Wales, 1999. / Also available online.

Thesis (Ph.D.) -- University of Adelaide, Dept. of Medicine, 2000. / Bibliography: leaves 363-421.

Thesis (Ph.D.) -- University of Adelaide, Dept of Anatomical Sciences, 2003? / Bibliography: leaves 262-298.

Thesis (M.Sc.) --University of Adelaide. / Typewritten copy.