These SREs are refugees of historical climate change. Millions of years ago, Australia was a wetter place and as the continent move northwards, and the circum-polar current developed, Australias climate became drier. As the continent dried, the distributions of species that were dependent on wetter conditions contracted to areas that were still able to maintain necessary moisture levels. Millenia of isolation in these mesic patches has frequently lead to speciation and each range or drainage system may have their own assemblages of SREs. Habitats that typically support relictual SREs include:

• south facing hill slopes, especially those sheltered from fire
• gorges and gullies sheltered from fire
• scree slopes or bolder piles
• riparian woodland
• woodland thickets that are sheltered from fire
• isolated artesian springs
• mountain top forests

In Western Australia, many relictual SREs appear to be able to survive dry periods by moving deep into soil, rockpiles and or leaflitter and are only readily sampled on the surface after ‘good’ periods of rain. Detecting these species during dryer periods may be difficult and time consuming if not impossible.

Dinocambala ingens (Darling Scarp banded millipede)

Orphnaeus sp. (Glowing soil centipede)

Bothriembryon sp. (land snail)

Nunciella sp. (harvestman)