Background

The fossils in my collection were collected on field trips in 2009 and 2012 from Mulbring Quarry near the township of Mulbring and Aberdare State Forest near Cessnock. The fossils were lawfully acquired with permission of private property owners as organised by the field trip coordinators. 

The fossil specimens date from the Middle Permian ~250 Ma and are located in the Fenestella Shale which forms part of the Branxton Formation, Maitland Group, lower Hunter Valley. Both localitites feature exquisite examples of marine Permian fauna.   

Australia 250 Ma was located in the south polar region and was part of the Gondwana supercontinent which consisted of present day South America, Africa, India, Australia, New Zealand and Arabia. At this time the climate was cool temperate with pockets of glaciation and annual ice covering and also pockets of forests full of diverse flora. Both fossil sites contain evidence of glaciation and frequent ice covering with the presence of drop stones and wood debris found at both sites. 

Figure showing the change in position of the South Pole throughout the Paleozoic. Source: http://www.ncdc.noaa.gov/paleo/ctl/cliscibeyond.html

There was also extensive volcanism along the east coast of Australia. Evidenced at the fossil localities by the volcanic striated drop stones. Large inland seas also dominated parts of the continent at this time. The fossils in my collection are all marine specimens typical of shallow marine environments. 

References

Excursion Handout Permian fossils and palaeoenvironments of the Hunter Valley 
Monroe, M.H. 2008. The Permian Period 286-245 Ma. In http://austhrutime.com/permian_period.htm. Accessed 30.10.12.
Percival, I.G. 1979. The geological heritage of New South Wales, volume 1. Geological Society of Australia, Sydney.