Comparative three-dimensional jaw muscle anatomy of marsupial carnivores (Dasyurus spp.) and the termite-eating numbat (Myrmecobius fasciatus).

Among marsupials, the endangered numbat (Myrmecobius fasciatus) is the only obligate myrmecophage with a diet comprised strictly of termites. Like many other specialised myrmecophagous mammals, numbats have a gracile and highly specialised skull morphology with an elongated rostrum and small braincase. Myrmecobiidae is one of four taxonomic families within the Australasian marsupial order Dasyuromorphia, and to date, the muscular anatomy of any member of this group is relatively poorly known.

A review of the late Cenozoic genus Bohra (Diprotodontia: Macropodidae) and the evolution of tree-kangaroos.

Tree-kangaroos of the genus Dendrolagus occupy forest habitats of New Guinea and extreme northeastern Australia, but their evolutionary history is poorly known. Descriptions in the 2000s of near-complete Pleistocene skeletons belonging to larger-bodied species in the now-extinct genus Bohra broadened our understanding of morphological variation in the group and have since helped us to identify unassigned fossils in museum collections, as well as to reassign species previously placed in other genera. Here we describe these fossils and analyse tree-kangaroo systematics via comparative osteology.

Uterine Tube Resection by Vaginotomy as an Alternative to Ovariectomy in Mature Cattle.

The prevention of pregnancy is desirable for female cattle destined for sale in the northern Australian rangelands for both economic and welfare reasons. Controlled access to bulls is often not feasible, nor are any non-surgical methods currently available. Many females are therefore surgically spayed.

Keeping an ear out: size relationship of the tympanic bullae and pinnae in bandicoots and bilbies (Marsupialia: Peramelemorphia).

Bandicoots and bilbies (Order Peramelemorphia) occupy a broad range of habitats across Australia and New Guinea, from open, arid deserts to dense forests. This once diverse group has been particularly vulnerable to habitat loss and introduced eutherian predators, and numerous species extinctions and range retractions have occurred. Understanding reasons for this loss requires greater understanding of their biology.

Fang shape varies with ontogeny and sex in the venomous elapid snake Pseudonaja affinis.

A predator's preferred prey often changes over the course of its life as it grows from an inexperienced juvenile through to a sexually mature adult. For species with highly specialised feeding strategies, this may require its anatomy to change over the course of its life. The dugite (Pseudonaja affinis, Günther 1872) is a venomous snake from Australia that displays such a diet shift, with juveniles feeding on small reptiles, while adults mainly target mammals.

The skeleton of , a semiarboreal kangaroo from the Pleistocene of southern Australia.

The macropodine kangaroo, , was first described in 1989 from a Pleistocene deposit within Mammoth Cave, southwestern Australia, on the basis of a few partial dentaries and maxilla fragments. Here, we recognize within the Pleistocene assemblages of the Thylacoleo Caves, south-central Australia, where it is represented by several cranial specimens and two near-complete skeletons, a probable male and female. We reallocate this species to the hitherto monotypic genus .

Ontogenetic growth and the development of a unique fibrocartilage entheses in Macropus fuliginosus.

Here we examine the bone histology of the femora and humeri of the Western Grey Kangaroo, Macropus fuliginosus. Our results reveal that bone modelling in response to ontogenetic growth and the development of tuberosities on the femur, and especially in the humerus, lead to a highly complex histology. We propose that the alternating fast and slow rates of bone deposition are seasonal, and are likely correlated with heterothermy related to ecological constraints during the summer months.

Extreme bilateral polydactyly in a wild-caught western grey kangaroo.

Polydactyly is a congenital malformation resulting from an autosomal dominant mutation manifesting as supernumerary digits of the hands or feet. It is most commonly reported in humans and domestic mammals, though there have also been isolated examples across a range of wild vertebrate species. Here we report a case of extremely unusual bilateral preaxial polydactyly on the pectoral limbs of a male western grey kangaroo (Macropus fuliginosus) from the South West region of Western Australia, in which two supernumerary digits were present on each manus.

Review of the methods used for calculating physiological cross-sectional area (PCSA) for ecological questions.

This review examines literature that used physiological cross-sectional area (PCSA) as a representative measure of an individual muscle's maximal isometric force production. PCSA is used to understand the muscle architecture and how a trade-off between muscle force and muscle contractile velocity reflect adaptations of the musculoskeletal system as a reflection of functional demands. Over the decades, methods have been developed to measure muscle volume, fascicle lengths, and pennation angle to calculate PCSA.

Covariation between forelimb muscle anatomy and bone shape in an Australian scratch-digging marsupial: Comparison of morphometric methods.

The close association between muscle and bone is broadly intuitive; however, details of the covariation between the two has not been comprehensively studied. Without quantitative understanding of how muscle anatomy influences bone shape, it is difficult to draw conclusions of the significance of many morphological traits of the skeleton. In this study, we investigated these relationships in the Quenda (Isoodon fusciventer), a scratch-digging marsupial.

Mechanical similarity across ontogeny of digging muscles in an Australian marsupial (Isoodon fusciventer).

Many mammals dig, either during foraging to access subsurface food resources, or in creating burrows for shelter. Digging requires large forces produced by muscles and transmitted to the soil via the skeletal system; thus fossorial mammals tend to have characteristic modifications of the musculoskeletal system that reflect their digging ability. Bandicoots (Marsupialia: Peramelidae) scratch-dig mainly to source food, searching for subterranean food items including invertebrates, seeds, and fungi.

Anatomy of the cavernous muscles of the kangaroo penis highlights marsupial-placental dichotomy.

The mammalian penis is a complex hydraulic organ of cavernous (spongy) tissue supported by both smooth and skeletal muscle structures. In placental mammals, the paired ‎Musculus ischiocavernosi anchor the corpora cavernosa to the pelvis (at the ischium), and the paired M. bulbospongiosi converge as they envelop the base of the corpus spongiosum.

The fibular meniscus of the kangaroo as an adaptation against external tibial rotation during saltatorial locomotion.

The kangaroo knee is, as in other species, a complex diarthrodial joint dependent on interacting osseous, cartilaginous and ligamentous components for its stability. While principal load bearing occurs through the femorotibial articulation, additional lateral articulations involving the fibula and lateral fabella also contribute to the functional arrangement. Several fibrocartilage and ligamentous structures in this joint remain unexplained or have been misunderstood in previous studies.

Forelimb Myology of Carnivorous Marsupials (Marsupialia: Dasyuridae): Implications for the Ancestral Body Plan of the Australidelphia.

Carnivorous marsupials of the family Dasyuridae represent a more generalized anatomical condition of both craniodental and postcranial features in comparison to other groups of Australidelphian marsupials. Plesiomorphic characters include polyprotodont dentition, didactylous (rather than syndactylous) pedal morphology, the retention of clavicles and epipubic bones, and an unossified patelloid. In light of the anatomy of the postcranial skeleton, we hypothesized that the muscular anatomy of the Dasyuridae would likely display a range of plesiomorphic traits.

Functional morphology of the forelimb of living and extinct tree-kangaroos (Marsupialia: Macropodidae).

Tree-kangaroos are a unique group of arboreal marsupials that evolved from terrestrial ancestors. The recent discovery of well-preserved specimens of extinct tree-kangaroo species (genus Bohra) within Pleistocene cave deposits of south-central Australia provides a unique opportunity to examine adaptive evolution of tree-kangaroos. Here, we provide the first detailed description of the functional anatomy of the forelimb, a central component of the locomotor complex, in the extant Dendrolagus lumholtzi, and compare its structure and function with representatives of other extant marsupial families.

Comparative jaw muscle anatomy in kangaroos, wallabies, and rat-kangaroos (marsupialia: macropodoidea).

The jaw muscles were studied in seven genera of macropodoid marsupials with diets ranging from mainly fungi in Potorous to grass in Macropus. Relative size, attachments, and lamination within the jaw adductor muscles varied between macropodoid species. Among macropodine species, the jaw adductor muscle proportions vary with feeding type.

An arid-adapted middle Pleistocene vertebrate fauna from south-central Australia.

How well the ecology, zoogeography and evolution of modern biotas is understood depends substantially on knowledge of the Pleistocene. Australia has one of the most distinctive, but least understood, Pleistocene faunas. Records from the western half of the continent are especially rare.