Australian Museum

Monotremes arose in southern polar environments and were restricted to high latitudes for most of their evolutionary history, explaining their limited global distribution. They may be specialised dryolestids, primitive mammals with a near-global distribution in the Jurassic–Cretaceous. The oldest monotreme fossils are from the Early Cretaceous – 126 million-year-old (Ma) teeth and jaws from southern Victoria, representing a mouse-sized species (Teinolophos trusleri) which had an elongated snout that was used to probe for food. It lived at 76°S, enduring freezing temperatures and 3 months of total darkness each year. The next oldest monotremes, also from southern Victoria, date to 113–108 Ma. They were at least an order of magnitude larger than Teinolophos, around the size of modern Platypus Ornithorhynchus anatinus and echidnas. By the Late Cretaceous (ca. 100 Ma), an age of monotremes had opened in the Australian part of the Gondwanan continent, with six monotreme genera (but no other mammals) co-existing at 60°S at what is now Lightning Ridge, northern NSW. They included an ancestral platypus, another species that was structurally annectant to platypus and echidnas, and a variety of rat to small pig-sized types that appear to have occupied aquatic and terrestrial niches. There are no monotreme fossils yet known from Australia between 100 and 24 Ma, but ancestral platypus, dating to around 70–64 Ma, are known from southern South America. Fossils of toothed platypus (Obdurodon) from central Australia date to around 26 Ma. These are the earliest known non-polar monotremes, living at around 40°S. Rare toothed platypus fossils occur 24–13 Ma, but the oldest known toothless platypus (Ornithorhynchus) date to the Pleistocene (2.5 Ma – 10 ka). After having teeth for 100 million years, Platypus may have lost them because of competition with Water Rats Hydromys chrysogaster. The oldest well-dated echidna fossils are Pleistocene, but genetic studies suggest that the lineage dates back to ca. 50 Ma. Echidnas may have evolved from platypus-like relatives that became isolated on the margin of the paleo-continent Sahul such as on the Vogelkop Island 50–30 Ma. They may have then re-invaded mainland Sahul (i.e. Australia and New Guinea) in the Late Pliocene–Early Pleistocene.

Davisassiminea, a new genus of the Assimineidae, is proposed for Rissoa (Cingula) capensis G. B. Sowerby III, 1892 from tidal flats of southeastern South Africa. The new genus is unique for the family in the morphology of the radula and reproductive system, and the absence of distinct omniphoric grooves. A congeneric species, Assiminea globulus Connolly, 1939, was also examined anatomically. Our molecular phylogenetic analysis using two mitochondrial genes and one nuclear gene confirms that these taxa are members of the subfamily Assimineinae. Based on molecular and radular evidence, Microsetia durbanensis Tomlin, 1916 is also a member of the new genus. Uniquely for assimineids, these species live on seagrass in marine habitats.

Abstract Christmas beetles (subfamily Rutelinae, genera Anoplognathus , Calloodes and Repsimus ) are an ecologically important and culturally significant group of Australian scarabs, known for their striking appearance and seasonal mass emergences. Over the last decade, anecdotal reports suggest widespread population declines, raising concerns about their conservation status. Despite their prominence in Australian ecosystems, critical deficits remain in our understanding of their biology, particularly regarding their feeding ecology and larval habitat requirements. We reviewed available literature regarding adult and larval Christmas beetle feeding ecology, particularly feeding preferences, host plants and food finding behaviours. Our literature review found significant gaps in our knowledge of Christmas beetle feeding ecology: adult host plant association data were available for only 25 of the 44 described species of Christmas beetles. For larvae, our literature search identified feeding ecology information for only nine species. With the exception of a single study, all data regarding larval feeding came from observational studies rather than feeding trials. Notably, the only feeding trial we found failed to identify the larvae to species, significantly limiting the applicability of its findings. The limited information identified in this review highlights the urgent need for targeted research into the feeding ecology of Christmas beetles. The scarcity of data on larval feeding, in particular, limits our ability to determine how changes in land use, soil conditions, and plant communities impact their populations. Future studies incorporating feeding trials, long‐term field observations, and experimental approaches will be critical for better understanding Christmas beetle ecology, especially for assessing their ecological roles, identifying key habitats, and developing effective conservation strategies where needed. Given the increasing concerns over Christmas beetle declines, prioritising research on their habitat requirements and resource use will help to ensure the conservation of these iconic Australian insects.

Molecular data are widely used to resolve complex phylogenetic relationships between cryptic species, particularly in cases where morphological features are insufficient to confirm taxonomic distinctness. For benthic shallow-water octopuses, several successes and failures have been reported when attempting to delineate species using individual nuclear or mitochondrial markers. In this study, we investigated the potential of shallow random shotgun sequencing to assess the phylogenetic placement of an undescribed southern hemisphere lineage within the Octopus vulgaris species complex, which could not be conclusively delimited using single-marker approaches. A total of 338 nuclear loci, along with complete mitochondrial genomes, were generated for two specimens presently classified as Octopus vulgaris (Type III) that originated from the southeastern Atlantic coast of South Africa and Amsterdam Island in the southern Indian Ocean. Our combined phylogenomic approach reveals that this lineage is genetically distinct from O. vulgaris sensu stricto (ss) from the Mediterranean and the northeast Atlantic, as well as from the closely related O. sinensis from East Asia. A further separation of O. vulgaris (Type III) into distinct South African and Amsterdam Island lineages cannot be proven. These findings add to the growing body of evidence that supports O. vulgaris Type III as a genetically distinct lineage within the O. vulgaris species complex, and emphasise that the taxonomic classification of this southern hemisphere lineage warrants re-evaluation.

As climate change intensifies, maintaining genetic diversity of natural populations is crucial to safeguard ecosystem integrity and adaptive potential. The Southern Ocean encompasses 10% of the Earth's oceans1 and contains a taxonomically diverse ecosystem with an extraordinarily high level of endemism (50%-90%).2,3,4 As one of the fastest-changing regions on Earth, the Southern Ocean is currently under threat from climate change5 and anthropogenic stressors, including fishing and tourism.6 Targeted marine protected areas (MPAs) are popular and effective mechanisms for limiting anthropogenic stressors in sensitive marine ecosystems.7 Approximately 78% of Southern Ocean species are benthic invertebrates,4 and most modern benthic taxa radiated in situ over the last 14 million years,8 alongside adaptation to withstand polar conditions.9 However, their genetic information has not yet been synthesized across the region to determine priority areas for genetic conservation. Using a multi-species genetic landscape approach from 28 benthic marine invertebrate species examined at a population level, we identified hotspots of nucleotide diversity, haplotype diversity, genetic divergence, and genetic connectivity comprising 3,455,799 km2 of the Southern Ocean. Only ∼28% of all identified genetic hotspots are currently being protected by established MPAs. Maintaining established and adopting proposed MPAs would protect ∼54% of all hotspots. The Southern Ocean is likely to face a high risk of ecosystem failure unless ecosystem resilience is sustained.10 Targeted areas to safeguard Southern Ocean benthic biodiversity, informed by genetic knowledge, are now readily available for conservation assessments.

Abstract Despite extensive research on the western Pacific crown-of-thorns starfish (CoTS; Acanthaster cf. solaris ), especially from Australia’s Great Barrier Reef (GBR), there are persistent knowledge gaps that constrain understanding and management. Given renewed population irruptions of CoTS on the GBR, alongside escalating climate impacts and direct anthropogenic pressures, a quantitative assessment of knowledge gaps was undertaken to identify research priorities and guide future efforts. In this study, 27 experts independently scored 206 research questions across seven Themes and 39 topics, based on four different criteria ( Knowledge gap , Feasibility , Urgency , and Applicability ). These questions were ultimately rationalized into 170 distinct questions, with scores aggregated across merged questions. Management was the highest scoring Theme for Urgency , Applicability , and overall. All but six of the 20 top-ranked questions were from the Management Theme and mainly related to Culling and/ or Monitoring. Most questions (158 out of 170) also scored highly for Feasibility , suggesting that there are existing methods and technical capability available to advance the extensive and diverse range of research questions that were posed, if resources were made available. This quantitative assessment provides guidance on the prioritization of potential research that could improve management of CoTS populations to improve coral protection outcomes on the GBR. This study also suggests that there are limited constraints to undertaking necessary research to address many of the persistent knowledge gaps relating to CoTS.

Recent catastrophic climate events in Australia that have impacted millions of animals across a range of landscapes have initiated a need for planned and coordinated rescue responses. The platypus (Ornithorhynchus anatinus) is one of Australia’s most iconic and biologically significant species. At a workshop held at Healesville Sanctuary, Victoria, Australia in 2023, species experts discussed the greatest threats, scenarios where intervention may be required and the types of intervention options that may be suitable for platypuses. We consider drought to be the most concerning event for the species, along with the impact of cumulative events on their habitat over time. Here, we discuss how intervention criteria should consider the degree of habitat impact, the recovery time frame, the genetic importance and local extinction risk of a population, risks to animal welfare, and the capacity requirements and feasibility of resourcing any action. Suitable interventions are weighed against potential risks and include the rescue and rehabilitation of displaced individuals, in situ habitat support, and translocation to either temporary ex situ care or inter or intra catchment. Further research is required to address how the platypus responds during and after different climate events, to different interventions and to determine which populations are most at risk. The outcomes discussed here and the framework provided should aid in management response decision making after natural disasters that may impact platypus populations.

To date, only one species of the terebellid polychaete genus Thelepus Leuckart, 1849 has been described from Africa: T. pequenianus Augener, 1918. During a 2024 biodiversity survey in Arguin National Park (Mauritania), we discovered a second African species that we describe as Thelepus arguinensis sp. nov. It is characterised by notopodia restricted to only 20–35% of the body, three pairs of branchiae, each with numerous filaments, dorsal branchial gap absent, and thoracic uncini lacking a prow. Phylogenetic analyses of mitochondrial 16S and COI sequences confirm its distinctiveness from all congeners with available data. We also redescribe the polynoid Lepidonotus hupferi Augener, 1918 found sharing the tubes of some specimens of T. arguinensis sp. nov. and provide the first molecular data for the species, while extending its known distribution to Mauritania. This study documents a previously unreported facultative, likely commensalistic, association between the two species, highlighting both the underestimated diversity of West African polychaetes and the limited knowledge on the terebellid–polynoid relationships in the region.

Pseudoscorpions collected from the remote southeast Pacific Island of Motu Motiro Hiva (also known as Isla Salas y Gómez) yielded two different species. A juvenile specimen of the genus Garypus (Garypidae) was found near the seashore, which represents the most southerly record of Garypus in the Pacific Ocean. Numerous specimens of an unusual chernetid were taken from inside mummified carcasses of seabirds that breed on the island. Although they show morphological similarities to some other American genera such as Americhernes Muchmore, Cordylochernes Beier, and Lustrochernes Beier, the gaping fingers on the male chela and the positions of the trichobothria clearly differentiate them from all other genera. We therefore propose the new genus and species Motuchernes spatiodigitus sp. nov., which is endemic to this small remote and isolated island.

The diversity and distribution of species' traits in an ecological community determine how it functions. While modern fish communities conserve trait space across similar habitats, little is known about trait-space variation through deep time or across different habitats. We examined how fish trait diversity varies through space and time by comparing three Late Devonian fish communities — a tropical reef (Gogo, Australia), a tropical estuary (Miguasha, Canada), and a temperate freshwater system (Canowindra, Australia) — with six modern communities from diverse habitats. Trait-space metrics reflecting within-community diversity (functional richness) and species similarity (functional nearest-neighbour distance) indicated Late Devonian communities had scores similar to modern communities. However, they were less functionally rich than their closest modern analogues, and their species tended to be more functionally distinct from one another. Metrics describing location in trait space (centroid distances and hypervolume overlap) showed modern communities were similar to each other, Gogo and Miguasha were similar but distinct from modern communities, and Canowindra was distinct from all others. This pattern suggests period-associated differentiation and substantial heterogeneity among some Late Devonian communities. In addition to temporal changes, we found consistent differences associated with habitat type and climate zone. Reef and tropical communities were the most functionally rich, whereas functional nearest-neighbour scores were highest in estuarine and temperate communities. These results indicate fish community trait space varies with time, habitat and climate, suggesting ( i ) lability in fish trait space and ( ii ) that evolutionary history, environmental filtering, and stochasticity influence community assembly. • The functional trait space of fish communities reflects evolutionary history, habitat, and climate. • Devonian and modern fish communities differ in their trait composition. • Trait differences imply ancient communities functioned differently. • Habitat- and climate-related patterns in functional diversity metrics are consistent across time.