The first Cenozoic freshwater fish otoliths from Australia are described from the late Oligocene-Early Miocene Namba Formation from a borehole in northern South Australia. The borehole G8 was drilled in 1973 near Lake Pundalpa to a total depth of 450 ft and encountered, between 231 and 236 ft, a sandy interval of the lower Namba Formation containing well-preserved aragonitic fossils. Only eight otoliths were recovered, and they represent three different species, all of the Percichthyidae. They pertain to the extant genera Macquaria, Nannoperca? and Percalates, indicating the continued persistence of these freshwater fishes in Australia since that time. The most common species, and the only one that can be described to species level, is Macquaria pundalpa n. sp.Zoobank:
Museums are important repositories of palaeontological specimens that in some cases include historical collections that may be overlooked in contemporary studies. Fossil leaf impressions in silicified sandstone (=silcrete) from the deserts of northern South Australia, historically called the "desert sandstone", have been known since at least 1872. A small collection of leaf impressions (c. 40) from the desert sandstone were identified by Tate in 1896 as Northern Hemisphere genera such as Alnus, Bombax, Quercus and Magnolia, together with Australian genera. However, these fossils were only first described by Chapman in 1937, who identified some leaves as Banksia, Cinnamomum and Eucalyptus. Chapman also recognised Flindersia, Hakea, Hedycarya, Lomatia, Nothofagus, Persoonia and Tristania and assigned them principally to fossil and extant species previously reported from Paleogene-Neogene fossil localities in New South Wales and Victoria. Most fossil taxa were based on 1-2, rarely > 4 fossils. However, the assigned botanical affinity of these leaf fossils was justified inadequately and consequently the taxonomic entities require reassessment using modern concepts, as was the case for Banksia praegrandis, which was revised previously and the species transferred to a fossil genus as the new combination Banksieaeformis praegrandis. The Tate fossil collection was largely forgotten but was recently relocated in the South Australian Museum. In this report, these silcrete fossils are re-examined and their systematics reassessed. No support for Cinnamomum, Flindersia, Hedycarya, Nothofagus, Persoonia, Tristania and other genera amongst these fossils was sustained, though eucalypt-like leaves are confirmed, likely representing Corymbia and Eucalyptus s. str.
Five very large adult nematodes, measuring up to 30 cm long, were recovered from the peritoneal cavity of a male Boa constrictor found dead in a poultry breeding shed in the El Manantial rural settlement of the San Martin Region of Peruvian Amazonia, Peru. These four females and one male were identified as an undescribed species distinct at the subfamily level within the Cystoopsidae, a family containing nematodes which parasitise fish subcutaneously and the body cavity of reptiles. Although the worms were too poorly preserved to be completely characterised, it is unlikely that another infected Boa constrictor will be found in the foreseeable future.
A slightly ovoid impression from the mid Tonian-aged, Aspidella-bearing Heavitree Quartzite near Ormiston Gorge in central Australia strongly resembles the enigmatic, late Ediacaran-aged, Obamus coronatus fossil from the Nilpena National Heritage Site, west of the Flinders Ranges in South Australia. Dated at ca 850 Ma, the Ormiston Gorge impression trumps the occurrence of Obamus by some 290 million years, suggesting Obamus to have been a separate evolutionary event. This supports the contention that metazoan life initially evolved considerably earlier than the widely accepted date of 580 Ma and that evolution likely did not follow a continuum from conception to the present day. Rather, the evolution of metazoan life likely involved a series of local evolution and extinction events, possibly in more than one location and over several hundred million years, before environmental conditions were conducive for metazoans to proliferate and disperse globally.
We extracted citizen science records from iNaturalist and Atlas of Living Australia databases to examine the current extent of reported observations of the Australian water dragon (Agamidae, Intellagama lesueurii) in South Australia. This species is not native to South Australia, but there were 17 unique records spanning 1958- 2025; though we are dubious about the 1958 record. All records with specific location information focus within a 50-km radius of Adelaide. Six local government areas were represented, with 56% of records pertaining to I. lesueurii reported in the Adelaide Hills local government area. Records from Marble Hill and Basket Range are indicative of a possible established population, especially with one record pertaining to multiple individuals. Available photographic evidence showed individuals of the subspecies, I. lesueurii howittii. Records from Millbook and Highbury are also suggestive of possible populations established at either of those locations, with available photographic evidence showing individuals of the subspecies, I. lesueurii lesueurii. A plausible explanation for these extralimital occurrences is that they result from escaped or abandoned pets. This would account for individuals of both subspecies being observed, especially with the natural distribution of the nominated subspecies being more than 1000 km away.
Defining a moment in time when metazoan lifeforms initially evolved is a desired outcome within the geological community and the current widely accepted timeline is drawn at ca 580 Ma. This date approximates to the timing of the Gaskiers Glaciation and Acraman Asteroid Impact within the mid Ediacaran Period, yet there is a growing body of evidence that macroscopic organisms existed prior to that time. Fossils discovered within the early Ediacaran-aged Brachina Subgroup (ca 635-586 Ma), throughout and beyond the Flinders Ranges of South Australia, suggest that subgroup to be a stratigraphic interval pivotal to unravelling the history of macroscopic life, at least within the Adelaide Superbasin if not globally. In addition to the occurrence of numerous and widespread sessile cup-shaped and frondose lifeforms within the subgroup, two unusual structures, previously ascribed inorganic origins, may in fact represent either the activity of, or actual fossils of, ancient organisms. These structures involve a possible death assemblage of juvenile cup-shaped Ernietta-like organisms preserved within a gutter and a dendritic fan-shaped impression possibly made by either an endobenthic sediment-displacive organism or fungi.
Organic geochemical research at The University of Adelaide began in 1967 when the author embarked on a study of the hydrocarbons preserved in the Early Cambrian trilobite-rich Emu Bay Shale from the Stansbury Basin on Kangaroo Island and in the Late Proterozoic microfossiliferous McMinn Formation from the McArthur Basin, Northern Territory. Subsequently, this field of research in the Mawson Laboratories over the ensuing five and a half decades encompassed the sub-disciplines of biogeochemistry, palaeolimnology, palaeoclimatology and palaeoecology. The sediments, sedimentary rocks and fluids analysed range in age from Archaean to Holocene. This paper is a short account of that research and its outcomes, as documented in a large number of theses and publications.
Woody shrub encroachment into the understorey of grassy eucalypt woodland in temperate southern Australia is changing ecosystem processes and impacting associated biodiversity. We investigated the impact on avian species richness and abundance caused by the perennial native wattle Acacia paradoxa invading three woodland vegetation communities (Eucalyptus arenacea/E. baxteri, E. camaldulensis and E. leucoxylon). Identification of avian winners and losers in these developing novel ecosystems can guide land managers seeking appropriate management options when faced with insecure funding for ongoing and expensive on-ground actions. Changes in avian species composition and abundance were determined at 56 sites, stratified into four A. paradoxa cover categories, in three open eucalypt woodland habitats across four localities. A total of 1251 birds/71 species were recorded in 209 surveys in spring 2022. Avian species richness and abundance varied significantly among the four localities and three grassy woodland vegetation types, with 34% of species found in only one vegetation type. Invasion by A. paradoxa altered bird community structure, increasing local species richness but reducing landscape-level richness - especially in E. leucoxylon woodlands. Threatened and open-woodland specialist species declined with higher shrub cover, while shrub-nesting birds flourished. Differing avian community responses to increasing A. paradoxa cover were evident with similar numbers of flourisher, user and avoider species. Over 70% of species either used or benefited from shrub invasion, but 19 species declined in abundance. Effective management should prioritise early intervention in low-to-moderate shrub cover areas to support threatened species and maintain avian diversity.
Interest in coastal management is increasing globally, particularly in urbanised temperate regions where cumulative stressors have degraded biogenic habitats. This includes renewed shellfish reef conservation efforts including restoration and fish habitat management. However, fish-habitat interactions within and across shellfish reefs and habitat types, including taxonomic, behavioural and trait variability is understudied. Here, we investigated subtidal shellfish reef fish assemblages in Gulf St. Vincent near metropolitan Adelaide, South Australia, from restored oyster (Ostrea angasi) and natural pinnid (Pinna bicolor) reefs, in comparison to seagrass and bare sediment habitats. Fishes were surveyed with unbaited video stations and were analysed using multiple assemblage metrics. All habitats were found to support distinct fish assemblage compositions, with the highest fish abundances associated with seagrass meadows. Across structural habitats of shellfish reef and seagrass habitats, fish assemblages shared similar traits, behaviours and higher species richness compared to bare sediment habitats. These findings indicate that both restored and natural shellfish reefs can support distinct fish assemblages and reaffirms the fish habitat value of structural habitats. By investigating fish-habitat interactions using multiple fish assemblage metrics, we demonstrate an approach that expands knowledge of shellfish reef fish monitoring that is applicable to other restoration and seascape management efforts.
The South Australian bolide/meteorite impact cratering record has few confirmed impact structures, with only two confirmed impact structures (Acraman and Mount Toondina). Impact structures created by bolides require a range of diagnostic evidence for them to be considered proven or confirmed, with this including geophysical, geochemical and petrographic evidence. The evidence for an additional six suspected impact structures in South Australia that have been reported in the literature record is evaluated using the known diagnostic characteristics of bolide/meteorite impacts.
The northern Flinders Ranges, South Australia, have populations of the range-restricted fish Mogurnda clivicola living in spring-fed pools in otherwise dry creek beds. It is not known if there are annual variations in water quality that may affect these populations. The water quality parameters of temperature, pH, electrical conductivity and dissolved oxygen concentration were measured twice-yearly over the seven-year period 2018-2024. Other parameters of calcium, sodium, potassium, chloride and nitrate ion concentrations were measured for part of the monitoring period. Visits were made in April-June and August-September of each year. Measurements were made at, or close to, the same well-defined points along creek sections where the endangered Mogurnda clivicola was present at the time of measurement and sample collection. The first two years of the monitoring period were the driest at nearby Arkaroola since recording of rainfall commenced there in 1938. This drought period had little effect on both water quantity and quality at all but one site, indicating that the spring-fed nature of the habitats gives them increased resilience to the effects of reduced rainfall. The measured water quality parameters showed that all three monitored habitats will be resilient to reduced rainfall over the short to medium term and can be expected to provide viable ongoing habitat for Mogurnda clivicola.
This paper reviews geomorphological and Aboriginal archaeological records from the upper Riverland region of South Australia (SA) in the context of a change in sedimentary environments within the Murray River tract during the deglacial period c. 15 ka. This has traditionally been recognised as a transition from a lower to upper valley fill; the Monoman and Coonambidgal Formations, respectively. A programme of archaeological dating and survey on the Calperum and Pike floodplains near Renmark provides evidence of a significant change in the ways Aboriginal peoples had interacted with this riverscape after c. 15 ka, expressed as an abrupt development of large-scale shell middens. This change was concomitant with a shift from broad, bedload-dominated channels in the river to a regime more akin to the modern river - a shift from a palaeo to the modern Murray river system. In this paper, we propose that the complementary archaeological and geomorphological evidence should be used to redefine the Monoman-Coonambidgal boundary in the upper Riverland. The evidence also provides an opportunity to re-examine palaeoclimate narratives from the broader Murray-Darling Basin (MDB) against a record from the lower end of the system. Importantly, the research demonstrates a novel use of archaeological data in interpreting hydroclimate records.
Accurate identification of invasive marine species is essential for understanding species range expansions and developing taxon-specific surveillance tools. The globally invasive European green crab Carcinus maenas, and the Mediterranean green crab C. aestuarii, which has a more limited introduced range and is a lesser concern as a pest, can be difficult to distinguish morphologically and can also hybridise. Although the species are visually similar, it has been proposed that they can be distinguished using carapace morphometrics. In temperate South Australia, invasive Carcinus have been reported as C. maenas. This study aimed to confirm the identity of invasive Carcinus in South Australia using carapace morphometrics and mtDNA COI gene sequencing. Carapace width:length ratios of 1,311 Carcinus from South Australia were variable within sexes and corresponded to those of both C. maenas and C. aestuarii. However, COI sequencing of 59 of these crabs revealed similar to 100% sequence matches to C. maenas and diverged from C. aestuarii sequences on GenBank by an average of 11.5%. Results supported that the South Australian population is C. maenas and that intraspecific morphological variation prevents carapace ratios alone from distinguishing species of Carcinus. DNA sequencing should be used to confirm the species identity of crabs identified as Carcinus during new incursions.
The distributions of modern vertebrate species and their molecular phylogenetic relationships across southern mainland Australia point to a long and complex history of dispersal and vicariance shaped by climatic fluctuations and resultant vegetation shifts. Yet, there are relatively few Pleistocene vertebrate assemblages from the southern periphery that provide direct insight into which species lived where and when. Here we report on a new site, a cave-fill exposed high on Kiana Cliff on southwestern Eyre Peninsula, South Australia. The assemblage contains the remains of 17 mammal taxa, including six extinct kangaroos. Single grain thermally transferred optically stimulated luminescence (TT-OSL) dating reveals an age of 126 +/- 10 thousand years for the fossil-bearing sedimentary infill, marking the assemblage as likely to be of last interglacial age. The presence on Eyre Peninsula of some species known from both the south-east and south-west of the continent suggests the potential for interchange and dispersal across the southern margin of the continent during the last interglacial period, or during glacial periods on the then exposed continental shelf areas. For species unable to penetrate the arid interior of southern Australia, Eyre Peninsula may have played a significant role in their local persistence during interglacial periods, and their east - west dispersal during lower sea-level stages of past glacials.
Discovered within the sequence of Neoproterozoic metasediments upon a wavecut platform at Ochre Point, south of Adelaide, in South Australia, is an abundance of circular structures, primarily shallow cylindrical fossils with rounded to hemispherical bases and, less commonly, discoidal fossils of Aspidella. Emanating from the cores of some Aspidella are elongate attachments and on a sandstone surface encountered upon the adjacent clifftop is an impression of a partial frond. These features all occur within the finer-grained interbedded components of cyclical shales/siltstones with capping sandstones/quartzites that constitute the entire cliff and wavecut platform exposures between the beaches of Moana and Maslins. A similar abundance of circular/cylindrical structures is known only from the Moorillah Formation amid the Neoproterozoic Brachina sequence within the central Flinders Ranges, suggesting that this Ochre Point occurrence is its stratigraphic correlative. Together these fossils/trace fossils add to the growing list of organic features that pre-date, by possibly as much as 50 million years, the famed Ediacara macrofossils of the White Sea/Flinders Ranges Assemblage found elsewhere within the Ediacara and Nilpena members of the Rawnsley Quartzite in South Australia.
The larvae of marsh beetles, Scirtidae, are common in freshwater habitats in Australia but are usually ignored in faunal surveys. Most of the commoner genera found in open fresh water have been described, however, numerous larvae have been collected from the specious genera Austrocyphon and Nothocyphon that do not yet have a description. This paper describes those taxa which were known but not described at the time. In addition, it includes generic descriptions of the larvae of an Australian species of Contacyphon, and the larva of a species of Leptocyphon with a further report on its unusual colonial lifestyle and the great reduction of the breathing apparatus of larvae in this genus. Larvae were identified by rearing and/or by genetic matching using mitochondrial cytochrome c oxidase (COI) sequencing. In addition, using the available COI sequences, a phylogenetic analysis was undertaken which supported the monophyly of species in each of the genera Austrocyphon and Nothocyphon. Also evident was the phylogenetic distinction between these two genera and a group of taxa related to N. frater (Blackburn). We have placed these species in a new genus, Fratercyphon. This genus now includes the following three species previously in Nothocyphon; F. frater (Blackburn), F. amita (Zwick) and F. patruelis (Zwick). The monospecific genus Tasmanocyphon Zwick is supported as a distinct evolutionary lineage, as is the unique larva of "Strathgordon" described by Watts in 2014.
River regulation can isolate the river channel from its floodplain, reducing flooding and causing vegetation to decline. Inundating isolated floodplains with environmental flows can re-invigorate natural vegetation suffering from hydrologic alteration. The floodplain between Locks 5 and 7 along the lower River Murray in South Australia was inundated in summer 2005-2006 by a managed weir-pool surcharge. We observed a highly variable response to inundation in the frequency and spatial distribution of the perennial floodplain herb, Centipeda cunninghamii (common sneeze-weed). Generally, there was little change in C. cunninghamii abundance or distribution prior to the surcharge. At most sites, C. cunninghamii frequency declined immediately after the surcharge, presumably as existing plants died due to prolonged inundation. At one site, C. cunninghamii did not recover and disappeared. At the other sites, C. cunninghamii re-grew, either in the same location as it was prior to the surcharge, or on a different part of the floodplain. However, at these latter sites, C. cunninghamii tended to recolonise its original location in less than two years. The use of regulatory structures to reconnect river-floodplain ecosystems should be used more widely as this can have a positive environmental impact by altering both floodplain vegetation frequency and distribution.
There is no accepted protocol for determining the population of small fish in creeks with the physical characteristics that exist in the northern Flinders Ranges. There, Mogurnda clivicola occurs at only three locations typified by shallow water pools that are spring-fed, lack connection to other water bodies, and may have a thick growth of Typha domingensis within pools and at the margins. Here, we present a method to suit these conditions. We used four-steps to estimate the median range of the fish population for the years 2020-2024: (1) Determined the median number of fish captured during each of nine visits to our ten sampling sites. The ten sampling sites were spread along about 500 m of creek line; (2) Corrected this median number to account for not using baited traps as a sampling method during some visits; (3) Adjusted the corrected number to allow for fish that were present at a sampling site but not caught. This provided an average number of fish caught per 500 m of creek-line; (4) Extrapolated this number of fish per 500 m to the total fish population for the length of creek-bed containing water. Using this method, we concluded that the Mogurnda clivicola population in the permanent waters of Yuwanhinya, Weetootla and Nepouie springs was between 6066 and 12,118 individuals in 2020-2024. The previously published estimates of population size are likely to be underestimates. We also find that the number of M. clivicola at Nepouie Spring is greater than at Weetootla Spring.
