Main study sites in northeastern Australia

One of the challenges of working in academia is the constant need and pressure to secure research project funding. The main research funding body in the country is the Australian Research Council (ARC). They offer a number of schemes for supporting research, all of which are incredibly competitive.

In 2011, I applied for funding under a new ARC scheme called the Discovery Early Career Research Award (DECRA). The DECRA’s are intended for junior researchers, generally with less than five years post-PhD research experience. There was an incredible number of applicants in the round – over 3180 – for just 277 awards (success rate of less than 9%). The outcomes were announced in mid-November, and to my surprise and delight, my application was successful! My funding will secure my research program for the next three years.

My study will focus on developing a baseline understanding of faunal responses to climate change and environmental perturbations through the Quaternary in northeasternQueensland. The region is unique for the concentration of a vast array of well-documented Quaternary palaeoclimatic archives (e.g., deep marine pollen cores, records in lacustrine sediments, rainfall archives from speleothems, offshore ostracod and foraminifer geochemical records). Such records extend back several hundred thousand years, through numerous glacial-interglacial cycles, and document how the region’s climate and environments have evolved through to the present. Strikingly, they provide key information on the timing and duration of prehistoric dry intervals, and document a long-term trend in the weakening of the Australian Monsoon: patterns of climate change that mirror those that are predicted to continue into the future.

Diprotodon skeleton at Floraville

Although there is an increasingly robust model of Quaternary climate change for the region, a lack of well-documented faunal records hampers efforts to understand prehistoric biological responses to the climate perturbations. However, that is not through want of appropriate fossil sites, but rather, lack of investigation. Areas such as Chillagoe are renowned for their unique Pleistocene faunas and contain animals such as the enigmatic Quinkana fortirostrum (extinct terrestrial crocodile) and Propleopus chillagoensis (giant carnivorous rat-kangaroo), two species that are known from nowhere else on the continent. Yet, we have little or no knowledge of their palaeoecology, palaeobiology and extinction simply owing to a lack of significant investigation in the region (the last major studies in the area ceased in the 1970’s). Other areas such as Floraville contain remarkably diverse Plio-Pleistocene faunas (including both megafauna and smaller-bodied species), but only preliminary results have ever been published. Well-documented sites, such as Wyandotte, preserve highly significant faunal assemblages previously thought to date to around the time of terminal megafaunal extinctions, but they now require re-dating because the previously established dates are no longer accepted. It is clear that northeastern Australia can yield critical data for understanding ongoing patterns of faunal change.

A major goal of my project will be to quantify the precise timing, magnitude, rates of climatic and environmental changes, and the long-term response of northeastern Australia’s terrestrial faunas to such events. For this reason, fossil deposits with long depositional sequences and well-preserved faunal remains in potentially easily datable contexts will be the focus of the research. Strategically, this includes targeting fossil assemblages that represent accumulation at different times through interglacial/glacial cycles, both before and after the arrival of humans on the continent, as well as more recent deposits within the timeframe of European colonisation (such as Carrington Cave, a site that contains the introduced house mouse, Mus musculus).

I’m currently planning fieldwork for the upcoming year. In late May, I will be heading up to the BrokenRiverarea. Several fossil deposits have already been identified from caves in the area by my friend Doug Irvin, a long-serving member of the Chillagoe Caving Club. Through June-July, I will be trekking to the Floraville area, just south of the Gulf of Carpentaria. Fossils have been collected from the region for the past 40 years by my colleagues Prof. Michael Archer and Henk Godthelp, both of the Universityof New South Walesin Sydney. We’ll be visiting the main sites, collecting new fossil specimens and hopefully some dating samples. In 2011, we excavated one of Australia’s most complete Diprotodonskeletons. I collected some dating samples at the time, but am still waiting on the results.

Waterfall in the Leichhardt River, Floraville Crossing

I’ve almost completed my first manuscript relating to the project- a direct fossil dating study. The purpose of the study is to determine the age of the specimen and to demonstrate the utility of the direct fossil dating approach of museum specimens using U-series methods. The specimen, a maxilla of the extinct marsupial ‘tapir’ (Palorchestes azael) was collected from the cave in 1977 and curated into the fossil collections of theQueenslandMuseum before being sequestered for dating. The results demonstrate that the specimen is between ~137–199 thousand years old, thus, predating the hypothesised time of final megafaunal extinctions. The result is significant in that it is the most northerly mainland dated recorded for any of the extinct Australian megafauna and represents one of the youngest reliably dated records for the species. The stratigraphic relationship of the dated specimen to other fossils from the cave is unclear. I hope to be able to submit the manuscript to a journal in the next month or so.

With the fieldwork, lab work, and paper writing, it’s bound to be a busy year!