Efficient recovery of conodont elements from impure limestone and calcareous rock samples remains a persistent challenge due to the large volume of residue retained following digestion and heavy liquid separation. This study evaluates the effectiveness of magnetic separation, using a Frantz isodynamic separator, as a method for refining residue fractions and concentrating apatite-based conodont elements. Fifteen upper Cambrian to Devonian samples from across New South Wales (NSW) were processed and assessed using a combination of size fractionation, stepped magnetic separation, and targeted heavy liquid refinement. Magnetic separation reduced total residue mass by up to 98 wt%, greatly improving the efficiency of manual picking. Portable X-ray diffraction (XRD) and stereomicroscopic observation of magnetic fractions confirm systematic mineralogical partitioning, with diamagnetic and weakly paramagnetic phases (including apatite, quartz, and muscovite) enriched in higher-amperage or non-magnetic fractions, and iron oxides such as goethite concentrated at lower amperages. The results demonstrate that magnetic refinement offers a reproducible, cost-effective, and broadly applicable method for improving conodont recovery efficiency by reducing residue volumes and concentrating phosphatic elements. A brief biostratigraphic case study from the Rowena Formation of the Koonenberry Belt in far western NSW confirms the practical benefits of this technique. More broadly, XRD analysis reveals that fossil recovery potential is enhanced in residues with moderate, compositionally mature detrital input (typically quartz-rich), and is markedly reduced in residues dominated by Fe-oxide phases and phyllosilicates. Ryan C. Dwyer* [ryan.dwyer@dpird.nsw.gov.au], Geological Survey of New South Wales, W.B. Clarke Geoscience Centre, 947–953 Londonderry Road, Londonderry New South Wales 2753, Australia Yong Yi Zhen [yong-yi.zhen@dpird.nsw.gov.au], Geological Survey of New South Wales, W.B. Clarke Geoscience Centre, 947–953 Londonderry Road, Londonderry New South Wales 2753, Australia Andreas P. R. Bjork [andreas.bjork@dpird.nsw.gov.au], Geological Survey of New South Wales, W.B. Clarke Geoscience Centre, 947–953 Londonderry Road, Londonderry New South Wales 2753, Australia Jodie M. Rutledge [jodie@rutco.com.au], Geological Survey of New South Wales, W.B. Clarke Geoscience Centre, 947–953 Londonderry Road, Londonderry New South Wales 2753, Australia Nathaniel J. Henderson [nathaniel.henderson@dpird.nsw.gov.au], Geological Survey of New South Wales, W.B. Clarke Geoscience Centre, 947–953 Londonderry Road, Londonderry New South Wales 2753, Australia Daniel Logan [daniel.logan@dpird.nsw.gov.au], Geological Survey of New South Wales, W.B. Clarke Geoscience Centre, 947–953 Londonderry Road, Londonderry New South Wales 2753, Australia.

Biological soil crusts are widespread in modern deserts, and consist largely of cyanobacteria and lichens. They begin as thin films and interstitial microbial coatings of the soil (form species Neantia deformata), but through ecological succession and freeze-thaw processes become thicker rugose surfaces (form species Rivularites repertus), then rolling crusts (form species Pustularichnus rebeccahuntforsterae), and eventually pinnacled crusts (form species Pinnaculosum priscum gen. et sp. nov.). Terrestrial biological soil crusts are characterized by sharp open cracks due to local extension, and healed cracks due to radial growth, or other compressive expansion. These highly deviatoric local stresses reflect shrink-swell, growth-death, and precipitation-dissolution phenomena of soils. Furthermore, terrestrial crusts often cap massive beds with original bedding disrupted by authigenic growth of nodules or desert roses of calcic (Bk) or gypsic (By) horizons of palaeosols, and by fungal hyphae and other filamentous microbes. In contrast, subaqueous microbial features are flexuous, sinuously wrinkled, or domed, with smooth textures maintained by microbial mat growth. Subaqueous mats can also be eroded out as flakes or rolled into tubes because they are thin and overlie sediment with lamination or other forms of bedding. In contrast, terrestrial crusts are fractured by frost and desiccation, and do not survive erosion and redeposition. Form genera of fossilized microbial textures now reveal life on land well back into the Palaeoproterozoic. Gregory J Retallack [gregr@uoregon.edu], Department of Earth Sciences, University of Oregon. Eugene, OR 97403, USA.

The Lower Devonian Lilydale Limestone (Pragian) contains diverse invertebrate fossil faunas including Ostracoda. This contribution provides a taxonomic reassessment of these previously studied ostracod specimens. Twenty ostracod taxa are redescribed and illustrated Evlanella? sp.; Primitiella? sp.; Paraparchites uniumbonata; Paraparchites? sp.; Beyrichiopsis sp.; Bairdiocypris subtrigonalis; Bairdiocypris cf. subtrigonalis; Bairdiocypris sp. 1; Bairdiocypris sp. 2; Bairdiocypris sp. 3; Bairdiocypris sp. 4; Bairdiocypris? sp. 5; Microcheilinella s.l. lilydalensis; Microcheilinella s.l. semicultrata; Bairdia s.l. flexuosa; Bairdiacypris? halli; Bairdiacypris? sp.; Ampuloides? sp.; Gen. indet. 1; Gen. indet. 2; Gen. indet. 3. The problematic identity of some taxa relates to the internal mould state of preservation for all examined specimens. Tamara T.A. Camilleri* [tamara.camilleri@deakin.edu.au], Deakin University, School of Life and Environmental Sciences (Melbourne Campus), Victoria 3125, Australia. Museums Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia; Elizabeth A. Weldon [l.weldon@deakin.edu.au], Deakin University, School of Life and Environmental Sciences (Melbourne Campus), Victoria 3125, Australia. Museums Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia; Mark T. Warne [mark.warne@deakin.edu.au], Deakin University, School of Life and Environmental Sciences (Melbourne Campus), Victoria 3125, Australia. Museums Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia; Rolf Schmidt [RSchmid@museum.vic.gov.au], Museums Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia.

The fossil record of echidnas in Australia is scarce, narrow in time, and restricted in space. In particular, the apparent absence of the extinct large-bodied Owen’s Giant Echidna Megalibgwilia owenii from Victoria is unusual in light of its wide distribution across the continent’s southeast including Tasmania. This paper describes a partial cranium of M. owenii, collected historically from Foul Air Cave in the Buchan Caves Reserve of East Gippsland. It is the first example of Megalibgwilia identified from Victoria, and reconciles the taxon’s otherwise disjunct southern distribution across mainland Australia. Further collection-based surveys are required to improve the understanding of Quaternary fossil tachyglossid taxonomy and distribution. Tim Ziegler* [tziegler@museum.vic.gov.au], Museums Victoria Research Institute, GPO Box 666, Melbourne 3001, Victoria, Australia; Jeremy Lockett [jeremywlockett@gmail.com], Museums Victoria Research Institute, GPO Box 666, Melbourne 3001, Victoria, Australia; School of Life and Environmental Sciences, Deakin University, 221 Burwood Highway, Burwood 3125, Victoria, Australia.

Isolated opercula from the lower Cambrian (Series 2) of present-day high arctic Greenland represent a group of triplicatellid orthothecids (Class Hyolitha) that originally inhabited equatorial seas offshore from eastern Laurentia. With five species from the Aftenstjernesø Formation and one from the underlying Buen Formation, they comprise the most diverse known assemblage of Triplicatella, a genus originally established in South Australia but recognized subsequently from China, Laurentia and Siberia. A seventh species also from the Aftenstjernesø Formation is assigned to a new triplicatellid genus, Biplicatella, with type species Linevitus opimus from the Chengjiang biota of China. New species: Triplicatella paluaq, Biplicatella skovstedi from the Aftenstjernesø Formation of North Greenland. http://zoobank.org/urn:lsid:zoobank.org:pub:3280A2C8-5481-4106-8B39-78CDE3E0BC36 John S. Peel* [john.peel@pal.uu.se], Department of Earth Sciences (Palaeobiology), Uppsala University, Villavägen 16, Uppsala SE–75236, Sweden.

Nineteen trilobite species, including 10 new taxa, are reported from the lower Cambrian (Series 2, Stage 4, upper Ordian) First Discovery Limestone Member of the Coonigan Formation in the Koonenberry Belt of far western New South Wales, Australia. Previous reports of the brachiopod taxa Micromitra nerranubawu and Eothele granulata, along with the trilobites Redlichia and Onaraspis, support the unit being assigned to the lower Micromitra nerranubawu Zone. This is further confirmed by the trilobite fauna described herein, which shares its greatest similarity to age equivalent strata in the Amadeus Basin of the Northern Territory; common taxa include Olenoides percivali sp. nov., Pagetia silicunda (= Pagetia sp. cf. P. quebecensis), Xystridura fracta (=Xystridura gayladia), Gunnia fava, and Xingrenaspis krusei sp. nov. Other species level similarities include assemblages found in the upper Ordian and lower Templetonian sequences of the Daly, Georgina, Ord and Wiso basins. New species introduced include: Redlichia holmesi sp. nov., Onaraspis cymbricensis sp. nov., Dinesus shergoldi sp. nov., Dinesus whitehousei sp. nov., Olenoides lawrenceorum sp. nov., Olenoides percivali sp. nov., Onchocephalus? warrisi sp. nov., Xingrenaspis krusei sp. nov., Changqingia andersonorum sp. nov., and Solenoparia gnaltaensis sp. nov.

Prognathodon waiparaensis was a large-bodied mosasaurine mosasaur known from the latest Cretaceous of New Zealand. The holotype and only described specimen of the species has remained on display at the Canterbury Museum for more than 50 years after its initial description in 1971, during which time mosasaur systematics has substantially changed, and the generic placement of P. waiparaensis has come into question. Following 3D surface scanning of the holotype material, a redescription and comparison with more recently described species has revealed some minor changes to its initial description, including the identification of additional cranial material. Additional autapomorphies have been identified in a posterolateral pit on the coronoid and a large posterior projection on the axis intercentrum. The orientation of the two carinae on the marginal dentition ranges from anterior–posterior to anterior–labial throughout the jaw in a pattern that does not appear to have been previously reported in other taxa. An updated and rescored character dataset for P. waiparaensis has been inserted into a recently published phylogenetic character matrix, producing phylogenetic results that find P. waiparaensis to be sister to Prognathodon solvayi. The results also find polyphyly amongst Prognathodon species, and potential homoplasy amongst some of the characters diagnostic for the genus. Despite bearing many cranial morphological similarities with other Prognathodon members often related to a generalist diet that includes durophagy, the teeth of P. waiparaensis do not show the morphology or wear that is observed with other durophagous taxa, suggesting a difference in palaeoecology from many of its recognized congeners. George Young* [george.young@my.jcu.edu.au], College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia; Al Mannering [alman@slingshot.co.nz], Canterbury Museum, 11 Rolleston Avenue, Christchurch, 8013, New Zealand; Mark Fraser [mfraser@canterburymuseum.com], Canterbury Museum, 11 Rolleston Avenue, Christchurch, 8013, New Zealand; Paul Scofield [pscofield@canterburymuseum.com], Canterbury Museum, 11 Rolleston Avenue, Christchurch, 8013, New Zealand.

Understanding the microstructural diversity of mineralized shells in early molluscs is essential for reconstructing the origin of the phylum during the Cambrian Explosion. Here, we report the first occurrence of a bidirectional foliated aragonite microstructure in early molluscs from the Cambrian Terreneuvian Bayangol Formation in the Zavkhan Basin of southwestern Mongolia. This microstructural type, previously known only in Cambrian hyolith skeletons, is documented for the first time through detailed microstructural characterization of shells in three helcionelloid species: Bemella simplex, Latouchella korobkovi and Merismoconcha tommotica. Our study significantly expands the recognized diversity of shellmicrostructures in early molluscs, reinforcing the skeletal commonality and homology of biomineralization mechanisms shared byhelcionelloids and hyoliths. Xia Baige [xiabaige@stumail.nwu.edu.cn], Shaanxi Key Laboratory of Early Life and Environments, State Key Laboratory of Continental Dynamics and Department of Geology, Northwest University, Xi’an 710069, PR China; Li Luoyang* [liluoyang@ouc.edu.cn], Key Lab of Submarine Geosciences and Prospecting Techniques, Ministry of Education and College of Marine Geosciences, Ocean University of China, Qingdao 266100, PR China.

Guzhangian (late Middle Cambrian) agnostoids and trilobites are described from the Belvoir Road area, western Tasmania. The fauna comprises seven agnostoid species and six trilobite species. The specimen described here as Lisogoragnostus sp. may represent a new species. The trilobites include Conocoryphidae gen. et sp. indet., which probably represents a new genus. The age of the fauna is suggested to be within the Lejopyge laevigata Zone and possibly within the Lejopyge laevigata II Zone. This indicates that the fauna is the youngest known within the economically significant Mount Read Volcanics. James B. Jago* [jim.jago@adelaide.edu.au], Adelaide University, Mawson Lakes, South Australia 5095, Australia; Christopher J. Bentley [bigfossil@bigpond.com], 30 Albert Street, Clare, South Australia 5453, Australia; Keith D. Corbett [keith.corbett@bigpond.com], 35 Pillinger Drive, Fern Tree, Tasmania 7054, Australia.

The taxonomy and phylogenetic interpretations of the ‘small shelly fossil’ group traditionally called pelagiellids has a long and convoluted history, and has subsequently been labelled the ‘Pelagiella problem’. While there is general agreement that these fossils represent lophotrochozoans, Pelagiella and similar forms have often been regarded as members of various molluscan groups (especially helcionelloids or gastropods), as well as annelids. Recent description of paired bundles of chaetae-like structures in Pseudopelagiella exigua (formerly Pelagiella exigua) from the lower Cambrian Kinzers Formation in Pennsylvania, USA, has reignited the debate regarding the systematics of Pelagiella and comparable taxa. Here, we document a new example of exceptional preservation in ‘Pelagiella’ subangulata from the early Cambrian of the Flinders Ranges in South Australia, which is represented by bundles of elongate tubular structures positioned within the last whorl of two individual conchs. These three-dimensional structures have been phosphatized, with authigenic mineralization having taken place via nucleation on both the internal and external surfaces of the originally organic (presumably chitinous) tubes; this had resulted in two layers of calcium phosphate. Similar to both Orsten- and Doushantuo-type preservation, such phosphatization must have occurred relatively quickly before major post-mortem decay and disturbance, with the small conch providing an ideal microenvironment for this mode of fossilization. The elongate tubular structures in ‘P.’ subangulata are considered homologous to the chaetae-like structures seen in P. exigua, largely based on number, size, shape, and relative position within a turbiniform conch. Although this anatomical feature is somewhat comparable to annelid chaetae, the fine-scale morphological details of the distal terminations and surface microstructures required to support this interpretation are lacking in both taxa. Given that Pelagiella and other similar taxa exhibit an unusual mosaic of morphological features seen in molluscs and annelids, further taxonomic studies and additional discoveries of key anatomical structures are essential to resolve the systematics of this problematic, and potentially polyphyletic group. Stephanie A. Richter Stretton* [srichte2@myune.edu.au], Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia; Sarah M. Jacquet [jacquets@missouri.edu], Department of Geological Sciences, University of Missouri, Columbia, MO 65211, USA; Glenn A. Brock [glenn.brock@mq.edu.au], School of Natural Sciences, Macquarie University, Sydney, New South Wales 2109, Australia; Zhiliang Zhang [zhiliang.zhang@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China; John R. Paterson [jpater20@une.edu.au], Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia; Marissa J. Betts [marissa.betts@une.edu.au], Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia.