A project undertaken at Murdoch University, and supervised by A/Prof N Warbuton.
At least 36 muscles attach to the bony pelvis in mammals, providing complex and integrated mechanisms for locomotion and posture. There appear to be differences between the muscle arrangement in marsupials in comparison to placental mammals, suggesting fundamental differences in the development of these muscles, their role in locomotion and thus the evolution of locomotor systems.
The aim of this project will be to comprehensively describe and compare the muscles of the pelvic and thigh region across a wide diversity of marsupials from throughout Australia and the Pacific. This will involve collecting three-dimensional (3D) scans using contrast enhanced micro-Computed Tomography (CT) of marsupial cadavers to visualise the soft tissues including muscle fibres. Once scanned, anatomical dissection of specimens will enable the interpretation of the scans and the generation of a digital library of the anatomy of this region. This data will provide a baseline for answering many questions of the evolutionary history of marsupials and provide data for the analysis of both living and extinct species.
During dissection, muscles will be identified, and the origins and insertions recorded and mapped. Each muscle will be systematically removed and weighed. Measurement of muscle fibre architecture and the calculation of physiological cross-sectional area will be made to estimate potential force production within muscles.
Using geometric morphometric methods, pelvis bone shape and covariation with muscle architecture will be analysed following. This will involve placing landmark arrays onto digital scans of the bony pelvis to investigate the covariation between bone shape and muscle variables, providing the first comprehensive quantitate analysis of the evolution of pelvis shape across a wide diversity of mammals.
Anticipated outcomes and benefits: Australia is home to the highest levels of threatened mammalian biodiversity globally and yet federal government funding is largely, unavoidably, directed towards invasive species. The proposed program of work aims to shed new light on our unique marsupial fauna, correlating behaviour with functional anatomical measurements to develop a suite of morphological indicators that could be used on both living and extinct species. This has implications in the fields of animal ecology, ecosystems, and palaeontology, whereby researchers will be able to better predict the behaviour of extinct animals and develop models of historical biodiversity.
Economic, commercial, environmental, social and/or cultural benefits: In the short to medium term, there are social and environmental impacts for the Australian public. The species we will be working with are iconic Australian fauna, including species that the general population are well acquainted with, e.g., bilbies and bandicoots, but also those less well known, such as bettongs and potoroos. Through our well-established community outreach programs, sharing current scientific research enables the Australian public to engage with conservation of biodiversity on a local level, increasing public engagement with biodiversity conservation action.
Making use of valuable existing specimens to provide an accessible, digital collection of scans that will be shared open-source via Morphosource will provide a collaborative opportunity for the scientific community to access morphological data from specimens that are otherwise very difficult to procure. In many cases, the specimens that we have available to scan are from vulnerable or threatened species.