A project undertaken at Flinders University, and supervised by Bruno Buzatto
Australia contains one of the largest desert biomes in the world, covering two thirds of the continent. Some diverse arid-adapted groups of animals evolved from ancestors that inhabited rainforests in the geological past, and therefore these groups persisted in in isolated refuges during glacial periods.
The future long-term persistence of these animals is less likely under the current accelerated climate change, as such species are poor dispersers, with small species ranges confined to discontinuous habitats. This is called ‘short-range endemism’, which is common in land snails, trapdoor spiders, millipedes, scorpions, and other groups, rendering them highly vulnerable.
Figure 1.
The endemic group of burrowing scorpions (genus Urodacus) has diversified into different habitats, but especially in arid areas and their abundance in some ecosystems results in a large biomass, meaning that they are ecologically very important in these places.
Despite a few studies on behaviour, physiology and venom, the diversity and ecology of the group remain largely unknown. Moreover, whereas burrowing scorpions are very popular in the pet trade, our recent description of two species with identical external morphology suggests that less than 10% of Australian species of Urodacus are known to science. Burrowing scorpions represent one of the most successful diversifications across the Australian arid zone, and yet we know nearly nothing about their diversity, ecology, or morphological evolution.
Given their full coverage of the Australian continent, confinement to discontinuous habitats, restricted species ranges and suspected great undocumented diversity, these scorpions are a perfect model for endemic Australian dispersal-limited invertebrates. By identifying scorpion species and traits that persisted during times and in places predicted to be arid, we will predict species responses to future climates and extreme weather events.
The following aims will further our knowledge on the ecology and evolution of invertebrates that have survived the continent’s aridification:
- Generate a continental-scale phylogeny for Urodacus, identifying diversity hotspots that apply to other dispersal-limited invertebrates, given their shared biogeographical histories.
- Characterise adaptations that enabled scorpions to transition into the arid zone, identifying which species should be at higher extinction risk from future aridification.
- Measure the resilience of burrowing scorpions to fire impacts, investigating their inherent resistance to fire in their habitats and flexibility in burrowing behaviour.